Question

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

Options

• an acute angled triangle

• an obtuse angled triangle

• a right triangle

• an isosceles triangle

Answer 1

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

Explanation:

Let the angle of the triangle are 5x, 3x and 7x.

As we know that sum of all angle of triangle is 180°.

Now, 5x + 3x + 7x = 180°

15x = 180°

x = `(180^circ)/15`

x = 12°

Hence, the angle of the triangle are:

5 × 12° = 60°

3 × 12° = 36°

7 × 12° = 84°

All the angle of this triangle is less than 90 degree.

Hence, the triangle is an acute angled triangle.