+0  
 
0
57
1
avatar

In concave equilateral pentagon ABCDE, angle A=angle B= 105 degrees. What is the degree measure of E?

 Dec 3, 2020
 #1
avatar+114592 
+1

I think you have something like this  :

 

 

There is an interesting relationship here between the base angles and  the "wing"  angles  at  C and E

These  two angles  =  base angle measure  / 3 =    105 / 3 =   35°

 

FYI  -   the sum of the interior  angles = 540°

So....the  angle at D  =  540  - 2( 105 + 35)  =  540 - 2 ( 140) = 540 - 280  =  260°

 

 

cool cool cool

 Dec 3, 2020

43 Online Users

avatar
avatar