If the angles of a triangle are in the ratio 2:3:7, the triangle is:
A. acute.
B. isosceles.
C. obtuse.
D. right.
E. equilateral.
Represent the angles as 2x, 3x, and 7x.
2x + 3x + 7x = 1800
12x = 1800
x = 150. The an angles are 300, 450, and 1050. Since one angle is between 900 and 180 0, the triangle is called an obtuse triangle.