Homework Help

How am I supposed to find the measurements of angles B and C? Thanks in advance!...

user profile pic

hardworking-h... | (Level 2) eNoter

Posted May 2, 2013 at 10:49 AM via web

dislike 2 like

How am I supposed to find the measurements of angles B and C? Thanks in advance!

http://static.panoramio.com/photos/medium/89657789.jpg

1 Answer | Add Yours

Top Answer

user profile pic

durbanville | High School Teacher | (Level 1) Educator Emeritus

Posted May 2, 2013 at 11:37 AM (Answer #1)

dislike 1 like

To solve this problem, split the shape in half by drawing line BD.

Now we have triangle ABD and we know that AB=AD (given)

Therefore `/_B_(1)=/_D_(1)` (isosceles triangle)and we are given that angle A=90.

Therefore, as the angles of a triangle =180 deg and A = 90 deg

Therefore   `/_B_(1) =/_ D_(1)=45 deg` 

We also know that triangle BCD is isosceles as BC=CD

`therefore`  `/_B_(2)=/_D_(2)` and we know that angle D=65(given)

We have already calculated `D_(1)=45 deg`

`therefore /_D_(2) = 65-45 = 20 therefore /_B_(2)=20`

As the angles of a triangle = 180:`/_C= 180 - 20 -20=140`

Ans: Angle B= 65 deg and Angle C=140 degrees.

 

 

 

Sources:

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes