Question

The angles of a triangle are in the ratio 5 : 3 : 7. The triangle is

(A) An acute angled triangle

(B) An obtuse angled triangle

(C) A right triangle

(D) An isosceles triangle

Answer 1

(A) An acute angled triangle

Explanation:

According to the question,

The angles of a triangle are of the ratio 5 : 3 : 7

Let 5:3:7 be 5x, 3x and 7x

Using the angle sum property of a triangle,

5x + 3x +7x = 180

15x = 180

x = 12

Substituting the value of x, x = 12, in 5x, 3x and 7x we get,

5x = 5×12 = 60^o

3x = 3×12 = 36^o

7x = 7×12 = 84^o

Since all the angles are less than 90^o, the triangle is an acute angled triangle.

Therefore, option (A) is the correct answer.