In concave equilateral pentagon ABCDE, angle A=angle B= 105 degrees. What is the degree measure of E?
+128474 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°
