The ratio of the interior angle measures of a triangle is 1:4:5. What are the angle measurements.

18°, 72° and 90°.

Step-by-step explanation:

It is given that the three interior angles have the measurements which are in a 1 : 4 : 5 ratio.

Let us assume x, 4x, and 5x are the three angles.

Now, from the property of triangles, the sum of all the interior angles is 180°.

Therefore, x + 4x + 5x = 180

⇒ 10x = 180

⇒ x = 18

Therefore, the angles of the triangle are 18°, 72° and 90°. (Answer)