Answer:
Each base angle is 81°
Step-by-step explanation:
A pennant is in the shape of an isosceles triangle and the vertex angle is 18°.
An iscosceles triangle has two equal sides and two equal angles.
So assuming the base angles measure b° each;
b° + b° + 18° = 180° (angles in a triangle add up to 180°)
2b° = 180° - 18° = 162°
b = 162° ÷ 2 = 81°
So each base angle is 81°
