Question

The angles in a triangle are in the ratio 1:2:9
What is the size of the largest angle?

Answer 1

9+2+1= 12
180 / 12 =15
biggest angle = 9 so, 9 * 15 =135
135 is the answer

Answer 2

The largest angle of triangle is 135°.

Explanation:

Given : The angles in a triangle are in the ratio 1:2:9.

To find : What is the size of the largest angle?

Solution :

Let the ratio be 'x'.

The angles in a triangle are x, 2x, 9x.

We know the sum of the angles of triangle is 180°.

So,
`x+2x+9x=180`

`12x=180`

`x=(180)/(12)`

`x=15`

The angles of triangle are

x=15°

2x=2(15)=30°

9x=9(15)=135°

Therefore, The largest angle of triangle is 135°.