What is the measure of one angle in a right triangle?

In a right triangle, one angle is defined to be 90 degrees, which is the characteristic feature that distinguishes a right triangle from any other type of triangle. This right angle indicates that the triangle has one angle where the two sides meet at a straight angle, creating a perfect "L" shape. The other two angles in a right triangle are complementary, meaning they add up to 90 degrees together, but the specific measure of the right angle itself is always 90 degrees. Therefore, the measure of one angle in a right triangle is unequivocally 90 degrees. This is fundamental in geometry, especially when solving problems related to right triangles and their properties.