The degree measures of the angles of the triangle are related as 5:13:18. Find the degree measure

The degree measures of the angles of the triangle are related as 5:13:18. Find the degree measure of the smaller corner of the triangle.

1. Vertices of the triangle – A, B, C.

2. Suppose ∠А: ∠В: ∠С = 5: 13: 18.

3. Take x as the number of degrees per part.

4. We draw up an equation, taking into account that the total value of the interior angles of the triangle

is 180 °:

5x + 13x + 18 = 180 °;

36x = 180 °;

x = 5 °.

5. We calculate the value of the degree measures of the angles of the triangle ABC:

∠А = 5 x 5 = 25 °.

∠B = 5 x 13 = 65 °.

∠С = 5 x 18 = 90 °.

The smallest of them is ∠A. Answer:

∠А = 25 ° – the smallest of all interior angles of the triangle ABC