Answer:
The largest angle of triangle is 135°.
Step-by-step 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, [tex]x+2x+9x=180[/tex]
[tex]12x=180[/tex]
[tex]x=\frac{180}{12}[/tex]
[tex]x=15[/tex]
The angles of triangle are
x=15°
2x=2(15)=30°
9x=9(15)=135°
Therefore, The largest angle of triangle is 135°.
