Question

If angles of a triangle are in the ratio $5:3:7$, then the triangle is :

• A. an acute angled triangle
• B. an obtuse angled triangle
• C. a right triangle
• D. an isosceles triangle

Answer 1

The correct option is A an acute angled triangle

Angles of triangle are in the ratio $5:3:7$
Therefore,
$5x+3x+7x={180}^o$
$15x={180}^o$
$x={12}^o$
$5x=5\times 12={60}^o$
$3x=3\times 12={36}^o$
$7x=7\times 12={42}^o$
Since ,all angles are less than ${90}^o$
Therefore, the triangle is an acute angled triangle.