There are two equal sides of 10, which means this is an isosceles triangle. With an isosceles triangle, there are also two equal angles (25° each in this case). If angle D equals 25°, then angle F also equals 25°. Subtract angles D and F from the total degrees in a triangle.
Triangles Degrees= 180° total
Find angle E:
= total triangle degrees - < D - < F
= 180° - 25° - 25°
= 130°
ANSWER: Angle E is (B) 130°
Hope this helps! :)
