First, subtract 90° from 180°, since 180° is the sum of all the angles in a triangle.
180 - 90 = 90°.
Now, we can really just test out different sets of numbers in a 2:7 ratio until we find two that have a sum of 90°.
If you look closely, 2 + 7 is 9. So, using that logic, multiplying 2:7 by 10 would get you 20° and 70°, which have a sum of 90°.
So the measures of the missing 2 angles is 20° and 70°.
Hope I helped!
