A geometry problem by Paola Ramírez

Geometry Level 1

In the following image, find x x in degrees.


The answer is 67.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

6 solutions

Rishabh Tiwari
May 18, 2016

3y = 180º - 59º = 81º...(exterior angle property)→→

→y = 27º

→Now by angle sum property ,

2y + 59º + x = 180º

→x = 180º - 113º = 67º... Ans :-D

First, we consider G I F \triangle GIF . Let the green colored angle be a a . Since I F B IFB is a straight line and a straight line is 18 0 180^\circ ,

a = 18 0 14 0 = 4 0 a=180^\circ-140^\circ=40^\circ

Now, we consider E G F \triangle EGF . Let the blue colored angle be 3 y 3y . We know that the sum of the interior angle of a triangle is 18 0 180^\circ , so

3 y = 180 59 a = 180 59 40 = 8 1 3y=180-59-a=180-59-40=81^\circ

It follows that,

y = 2 7 y=27^\circ

Now, consider G I F \triangle GIF again. Let the purple colored angle be c c . Then

c = 180 y a = 180 27 40 = 11 3 c=180-y-a=180-27-40=113^\circ

Let the yellow colored angle be x x . Since H I F HIF is a straight line, we have

x = 180 c = 180 113 = 6 7 x=180-c=180-113=\boxed{67^\circ}

Best solution thanks Sir

VIKASH MAURYA - 2 years, 11 months ago

You are welcome.

A Former Brilliant Member - 1 year, 4 months ago
Hana Wehbi
May 18, 2016

y = ( 180 59 40 ) / 3 = 27 y=(180-59-40)/3=27

Then 180 59 2 ( 27 ) 180-59-2(27) = x = 67 x=67

Typo: 2 ( 27 ) -2(27)

Hung Woei Neoh - 5 years ago

Log in to reply

Thank you, i will fix it.

Hana Wehbi - 5 years ago

you changed your name!!

Mohammad Khaza - 2 years, 11 months ago
Shashi Kamal
Aug 15, 2018

3y=81 so y=27 now x=y+40 (exterior angle is equal to sum of opposite two interior angles) so x=27+40=67°

Edwin Gray
Jun 21, 2018

The supplement of 140 = 40. So 3y + 59 + 40 = 180, 3y = 81, y = 27. The supplement of x is 180 - x. So y + 40 + 180 - x = 180, x = y + 40 = 67. Ed Gray

A straight line is 18 0 180^\circ . Thus,

a + 140 = 180 a+140=180 \implies a = 40 a=40

The sum of interior angles of triangle is 36 0 360^\circ . Thus,

3 y + 59 + 40 = 180 3y+59+40=180 \implies y = 2 7 y=27^\circ

By the exterior angle theorem, we have

x = y + a = 27 + 40 = x=y+a=27+40= 67 \boxed{67}

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...