Question 328008
To solve this problem, you are going to need to write two equations using what you know.
First, you know that you have a right triangle. This means that one angle is 90 degrees, and the sum of the two smaller angles must equal 90 degrees (because the sum of the angles of a triangle is 180):
A + B + C = 180 
90 + B + C = 180
B + C = 90 (where A is the right angle, B and C are the smaller angles)
Second, you know that the difference between the measures of the two smaller angles is 20 degrees:
B - C = 20 (where C is the smallest angle of the triangle)
This can be rewritten as B = 20 + C
Now plug in this second equation into the first equation and solve for C:
B + C = 90
(20 + C) + C = 90
20 + 2C = 90
2C = 70
C = 35
So the smallest angle is 35 degrees.