Finding the length of a side in an irregular quadrilateral, given three angle measures and two other sidesConstruct a Triangle from Given Base, Obtuse Angle Adjacent to Base and Difference of Two Other SidesFinding side and angle of isosceles triangle inside two circlesRelation between the GM of two sides of a triangle and the bisector of angle between themInside angle of a triangle with two sides of known ratio and one known side?Finding side of a triangle, given two sides and angle bisectorTwo sides of a triangle and the angle in between them are known. How to find the 3rd side?Help me find a side of a quadrilateral given one side and distance between the centers of two circles inscribed in the same quadrilateralFinding angle of irregular quadrilateral given all sides and one angleFinding an Angle using Cyclic Quadrilateral and Circle TheoremsFinding the length of the side of a triangle, given the lengths of the other two sides.
I probably found a bug with the sudo apt install function
XeLaTeX and pdfLaTeX ignore hyphenation
Why don't electron-positron collisions release infinite energy?
Copenhagen passport control - US citizen
How can bays and straits be determined in a procedurally generated map?
"which" command doesn't work / path of Safari?
What defenses are there against being summoned by the Gate spell?
How can I hide my bitcoin transactions to protect anonymity from others?
Is it possible to do 50 km distance without any previous training?
How to report a triplet of septets in NMR tabulation?
Find original functions from a composite function
Why is an old chain unsafe?
Infinite past with a beginning?
N.B. ligature in Latex
Do Phineas and Ferb ever actually get busted in real time?
Why are 150k or 200k jobs considered good when there are 300k+ births a month?
How can the DM most effectively choose 1 out of an odd number of players to be targeted by an attack or effect?
How to get the available space of $HOME as a variable in shell scripting?
What is the command to reset a PC without deleting any files
Do any Labour MPs support no-deal?
How is it possible for user to changed after storage was encrypted? (on OS X, Android)
Motorized valve interfering with button?
declaring a variable twice in IIFE
What do you call something that goes against the spirit of the law, but is legal when interpreting the law to the letter?
Finding the length of a side in an irregular quadrilateral, given three angle measures and two other sides
Construct a Triangle from Given Base, Obtuse Angle Adjacent to Base and Difference of Two Other SidesFinding side and angle of isosceles triangle inside two circlesRelation between the GM of two sides of a triangle and the bisector of angle between themInside angle of a triangle with two sides of known ratio and one known side?Finding side of a triangle, given two sides and angle bisectorTwo sides of a triangle and the angle in between them are known. How to find the 3rd side?Help me find a side of a quadrilateral given one side and distance between the centers of two circles inscribed in the same quadrilateralFinding angle of irregular quadrilateral given all sides and one angleFinding an Angle using Cyclic Quadrilateral and Circle TheoremsFinding the length of the side of a triangle, given the lengths of the other two sides.
$begingroup$

I'm struggling with finding the length $x$. It is obvious that $angle DCB = 150^circ$.
geometry
$endgroup$
add a comment |
$begingroup$

I'm struggling with finding the length $x$. It is obvious that $angle DCB = 150^circ$.
geometry
$endgroup$
$begingroup$
Extend $AD$ and $BC$ to meet at $E$. $ABE$ is then an equilateral triangle.
$endgroup$
– FredH
Mar 29 at 20:46
add a comment |
$begingroup$

I'm struggling with finding the length $x$. It is obvious that $angle DCB = 150^circ$.
geometry
$endgroup$

I'm struggling with finding the length $x$. It is obvious that $angle DCB = 150^circ$.
geometry
geometry
edited Mar 29 at 20:49
Blue
49.5k870157
49.5k870157
asked Mar 29 at 20:42
BobtrollstenBobtrollsten
7115
7115
$begingroup$
Extend $AD$ and $BC$ to meet at $E$. $ABE$ is then an equilateral triangle.
$endgroup$
– FredH
Mar 29 at 20:46
add a comment |
$begingroup$
Extend $AD$ and $BC$ to meet at $E$. $ABE$ is then an equilateral triangle.
$endgroup$
– FredH
Mar 29 at 20:46
$begingroup$
Extend $AD$ and $BC$ to meet at $E$. $ABE$ is then an equilateral triangle.
$endgroup$
– FredH
Mar 29 at 20:46
$begingroup$
Extend $AD$ and $BC$ to meet at $E$. $ABE$ is then an equilateral triangle.
$endgroup$
– FredH
Mar 29 at 20:46
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
Extend $overlineAD$ and $overlineBC$ to form an equilateral triangle $triangle ABE$. Then notice that $triangle EDB$ is a $30$-$60$-$90$ right triangle whose $sqrt3$ side is $5sqrt3$. Therefore, the length of $overlineDE$ is $5$, the length of $overlineBE$ is $10$ and $x=9$.
$endgroup$
$begingroup$
Is it possible that you show it on a diagram?
$endgroup$
– Bobtrollsten
Mar 29 at 20:51
$begingroup$
@Bobtrollsten If you follow the directions given, then you will see for yourself how this works.
$endgroup$
– John Douma
Mar 29 at 20:59
add a comment |
$begingroup$
Consider $Pin AD$ such that $CPparallel AB$. Then you have that $angle DCP=30°$. Finally $$tan(angle DCP)=tan(30°)=frac1sqrt3=fracx-45sqrt3$$ Thus
$$5=x-4iff colorredx=9$$
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function ()
return StackExchange.using("mathjaxEditing", function ()
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
);
);
, "mathjax-editing");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "69"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3167587%2ffinding-the-length-of-a-side-in-an-irregular-quadrilateral-given-three-angle-me%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Extend $overlineAD$ and $overlineBC$ to form an equilateral triangle $triangle ABE$. Then notice that $triangle EDB$ is a $30$-$60$-$90$ right triangle whose $sqrt3$ side is $5sqrt3$. Therefore, the length of $overlineDE$ is $5$, the length of $overlineBE$ is $10$ and $x=9$.
$endgroup$
$begingroup$
Is it possible that you show it on a diagram?
$endgroup$
– Bobtrollsten
Mar 29 at 20:51
$begingroup$
@Bobtrollsten If you follow the directions given, then you will see for yourself how this works.
$endgroup$
– John Douma
Mar 29 at 20:59
add a comment |
$begingroup$
Extend $overlineAD$ and $overlineBC$ to form an equilateral triangle $triangle ABE$. Then notice that $triangle EDB$ is a $30$-$60$-$90$ right triangle whose $sqrt3$ side is $5sqrt3$. Therefore, the length of $overlineDE$ is $5$, the length of $overlineBE$ is $10$ and $x=9$.
$endgroup$
$begingroup$
Is it possible that you show it on a diagram?
$endgroup$
– Bobtrollsten
Mar 29 at 20:51
$begingroup$
@Bobtrollsten If you follow the directions given, then you will see for yourself how this works.
$endgroup$
– John Douma
Mar 29 at 20:59
add a comment |
$begingroup$
Extend $overlineAD$ and $overlineBC$ to form an equilateral triangle $triangle ABE$. Then notice that $triangle EDB$ is a $30$-$60$-$90$ right triangle whose $sqrt3$ side is $5sqrt3$. Therefore, the length of $overlineDE$ is $5$, the length of $overlineBE$ is $10$ and $x=9$.
$endgroup$
Extend $overlineAD$ and $overlineBC$ to form an equilateral triangle $triangle ABE$. Then notice that $triangle EDB$ is a $30$-$60$-$90$ right triangle whose $sqrt3$ side is $5sqrt3$. Therefore, the length of $overlineDE$ is $5$, the length of $overlineBE$ is $10$ and $x=9$.
answered Mar 29 at 20:50
John DoumaJohn Douma
5,83521520
5,83521520
$begingroup$
Is it possible that you show it on a diagram?
$endgroup$
– Bobtrollsten
Mar 29 at 20:51
$begingroup$
@Bobtrollsten If you follow the directions given, then you will see for yourself how this works.
$endgroup$
– John Douma
Mar 29 at 20:59
add a comment |
$begingroup$
Is it possible that you show it on a diagram?
$endgroup$
– Bobtrollsten
Mar 29 at 20:51
$begingroup$
@Bobtrollsten If you follow the directions given, then you will see for yourself how this works.
$endgroup$
– John Douma
Mar 29 at 20:59
$begingroup$
Is it possible that you show it on a diagram?
$endgroup$
– Bobtrollsten
Mar 29 at 20:51
$begingroup$
Is it possible that you show it on a diagram?
$endgroup$
– Bobtrollsten
Mar 29 at 20:51
$begingroup$
@Bobtrollsten If you follow the directions given, then you will see for yourself how this works.
$endgroup$
– John Douma
Mar 29 at 20:59
$begingroup$
@Bobtrollsten If you follow the directions given, then you will see for yourself how this works.
$endgroup$
– John Douma
Mar 29 at 20:59
add a comment |
$begingroup$
Consider $Pin AD$ such that $CPparallel AB$. Then you have that $angle DCP=30°$. Finally $$tan(angle DCP)=tan(30°)=frac1sqrt3=fracx-45sqrt3$$ Thus
$$5=x-4iff colorredx=9$$
$endgroup$
add a comment |
$begingroup$
Consider $Pin AD$ such that $CPparallel AB$. Then you have that $angle DCP=30°$. Finally $$tan(angle DCP)=tan(30°)=frac1sqrt3=fracx-45sqrt3$$ Thus
$$5=x-4iff colorredx=9$$
$endgroup$
add a comment |
$begingroup$
Consider $Pin AD$ such that $CPparallel AB$. Then you have that $angle DCP=30°$. Finally $$tan(angle DCP)=tan(30°)=frac1sqrt3=fracx-45sqrt3$$ Thus
$$5=x-4iff colorredx=9$$
$endgroup$
Consider $Pin AD$ such that $CPparallel AB$. Then you have that $angle DCP=30°$. Finally $$tan(angle DCP)=tan(30°)=frac1sqrt3=fracx-45sqrt3$$ Thus
$$5=x-4iff colorredx=9$$
edited Mar 29 at 20:58
answered Mar 29 at 20:47
Dr. MathvaDr. Mathva
3,428630
3,428630
add a comment |
add a comment |
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3167587%2ffinding-the-length-of-a-side-in-an-irregular-quadrilateral-given-three-angle-me%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
$begingroup$
Extend $AD$ and $BC$ to meet at $E$. $ABE$ is then an equilateral triangle.
$endgroup$
– FredH
Mar 29 at 20:46