Question

3. The angle between two equal sides of an isosceles triangle is 52º.

Each of the equal sides is 18 cm long.
a) Determine the measures of the two equal angles in the triangle.
b) Determine the length of the third side.
c) Determine the perimeter of the triangle.

Answer 1

a) 64° each

b) 15.78 cm

c) 51.78 cm

Explanation:

a) (180 - 52)/2 = 64°

b) cos 64 = x/18, x = 7.89, 2x = 15.78 cm

c) 18 + 18 + 15.78 = 51.78 cm