In triangle ABC, angle A is 72 degrees, and angle B is 3 times the angle C.

In triangle ABC, angle A is 72 degrees, and angle B is 3 times the angle C. Find the degree measure of angle B and determine the shape of triangle ABC.

Let the angle C be equal to x, then the angle B is equal to 3 * x. As you know, the sum of the angles in a triangle is 180 degrees. Let’s make an equation, taking into account that the angle A is equal to 72 degrees:
x + 3 * x + 72 = 180;
4 * x = 180 – 72 = 108;
x = 108/4 = 27.
Thus, the angle C is 27 degrees, and the angle B is:
27 * 3 = 81.
All angles in a triangle are less than 90 degrees, so the triangle is acute-angled.
Answer: 81, acute-angled.