A certain triangle has two 45° angles. What type of triangle is it?

Answer is a right triangle. The angles of a triangle must add to 180 degrees.

You have two 45 degree angles

45 + 45 = 90

Now you need 1 more angle to equal 180

180 - 90 = 90

A right angle is 90 degrees. A right triangle has one right angle and two acute.