Question

Each of the two equal angles of an isosceles triangle is twice the third angle. Find the angles of the triangle.

Answer 1

Suppose the third angle of the isosceles triangle is x^o.
Then, the two equal angles are (2x)^o and (2x)^o.
Sum of the angles of any triangle is 180^o.

∴ 2x +2x+ x= 180
5x = 180
x = 36

Hence, the angles of the triangle are $36°,(2\times 36)°\mathrm{and}(2\times 36)°,\mathrm{i}.\mathrm{e}.36°,72°\mathrm{and}72°$.