Answer: 20, 70, 90
====================================================
Work Shown:
Let x be some positive real number.
Multiply each part of the given ratio by x to get 2x:7x:9x
So we have the three angles 2x, 7x, and 9x.
For any triangle, the three angles must add to 180
2x+7x+9x = 180
18x = 180
x = 180/18
x = 10
This leads to
The three angles of this triangle are: 20, 70, 90
This is a right triangle due to the 90 degree angle.