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 angled triangle d) an isosceles triangle

Answer 1

Step by step solution :

Let the angles be x. (5x,3x and 7x)

Sum of all angles of a triangle = 180°.

<A + <B + <C = 180°

5x + 3x + 4x = 180°

12x = 180°

x = (180/12)°

x = 15°

<A = 5x = 5×15 <B = 3x = 3×15

= 75° = 45°

<C = 7x = 7×15

= 105°

Answer :

a) Acute angled triangle = yes

b) Obtuse angled triangle = yes

c) Right angled triangle = no

d) Isosceles triangle = no