Answer:
[tex]\text{Equation: }2\angle B+\angle B=90\\\angle A=60^{\circ},\\\angle B=30^{\circ}[/tex]
Step-by-step explanation:
Complimentary angles are angles that add up to 90 degrees. Therefore, we can write the following system of equations:
[tex]\begin{cases}\angle A=2\angle B,\\\angle A+\angle B=90\end{cases}[/tex]
Solving, we obtain the equation:
[tex]2\angle B+\angle B=90,\\3\angle B=90,\\\angle B=\boxed{30^{\circ}}[/tex]
Plugging this back in to our first equation, we get:
[tex]\angle A=2(30)=\boxed{60^{\circ}}[/tex]