Answer:
The measure of the third angle is 60°.
Explanation:
We are given a right triangle that has a 90 degree and two other angles that are unknown.
Since one known angle is 90° and another angle given is 30° then the third angle must be 60°. All triangles must add up to 180°.
180° - 90° - 30° = 60°.
Here is an image of the demonstration/explaining types of triangles.