Question

A right triangle has one angle that measures 20°. What is the measure of the other acute angle?

Answer 1

All right angle triangles have to equal 180. So 20+90=110, 110-180=70. 70 is an acute angle because it is less than 90. If you want to check your work 20+70=90, 90+110=180

Answer 2

All the measures in a triangle equal 180 degrees.

We know that one angle equals 20 degrees.

A right triangle has a right angle, which equals 90 degrees.

90+20= 110

180-110= 70 degrees.

The acute angle is equal to 70 degrees. 

I hope this helps!
~kaikers