What is the measure of

Answer:
[tex]m\angle A=45\textdegree[/tex]
Step-by-step explanation:
All triangles have a sum of 180°. The problem shows us that two of the angles are 90° and 45°. Therefore, the last angle is 45°.
[tex]m\angle A+45+90=180\\m\angle A+135=180\\m\angle A=45[/tex]