Question

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

Answer 1

Let one angle be $x°$

And in an isosceles triangle two angles are equal.

So, the other two angles are $4x$.

We know that sum of all angles of a triangle is $180°$.

$$\begin{gathered} x+4x+4x=180° \\ 9x=180° \\ x=\frac{180°}{9}=20° \end{gathered}$$

So, the other angle is $4x=4(20°)=80°$

Hence, three angles of the triangle are $20°,80°,80°$.