Question

The measures of two angles of a triangle are 25° and 87°. Is the triangle acute, right, or obtuse? Explain.

Answer 1

The triangle is acute because the angles 25 and 87 are less than 90 degrees. 

Answer 2

180°- (25°+87°)= 180°-112°=68°
The triangle is acute because the measures of all angles of the triangle are less than 90°.