In a triangle the sides are 4 cm, 5 cm and 4 cm. One of the base angle is 80°. Find the measure of the apex angel.

In a triangle the sides are 4 cm, 5 cm and 4 cm. One of the base angle

1.	In a triangle the sides are 4 cm, 5 cm and 4 cm. One of the base angle is 80°. Find the measure of the apex angel.
A.	30°
B.	40°
C.	20°
D.	10°
Answer» D.