Answer: four 1. The vertex angle is 80°. The two base angles are 50° each. A. the 8 cm side is one of the two sides of equal measure. B. the 8 cm side is the base. 2. One of the base angles is 80°. The other base angle is 80° and the vertex angle is 20°. A. the 8 cm side is one of the two sides of equal measure. B. the 8 cm side is the base. Edwin