We will have the following:
First, we recall that a right triangle has a 90° angle.
We are also given that one of the other angles is 24°.
We also recall that the sum of all internal angles of a triangle add to 180°, so the following is true:
[tex]90+24+\theta=180\Rightarrow\theta=66[/tex]So, the measure of the missing angle is 66°.