Question

The ratio between a base angle and the vertical angle of an isosceles triangle is 1:4. Find each angle of the triangle.

Answer 1

Step: Find angles of triangle

Let each base angle of triangle = x

⇒ Vertical angle of triangle = 4x

∴ x + x + 4x = ${180}^{\circ }$

[ ∵ Angle sum property of a triangle]

6x = ${180}^{\circ }$

∴ x = ${30}^{\circ }$

4x = ${120}^{\circ }$

Hence, each angle of triangle are ${30}^{\circ }$, ${30}^{\circ }$ and ${120}^{\circ }$.