Answer
45$^{\circ}$
Work Step by Step
When the sum of the measures of the two positive angle is 90$^{\circ}$, the angles are called complimentary and the angle are compliment to each other.
a$^{\circ}$ and b$^{\circ}$ are complimentary angles therefore a$^{\circ}$ + b$^{\circ}$ = 90$^{\circ}$
If a is compliment to itself than b$^{\circ}$ = a$^{\circ}$
The compliment of angle a$^{\circ}$ is b$^{\circ}$which can be written as b$^{\circ}$ = 90$^{\circ}$ - a$^{\circ}$
Hence a$^{\circ}$ = 90$^{\circ}$ - a$^{\circ}$
a$^{\circ}$ + a$^{\circ}$ = 90$^{\circ}$
2a$^{\circ}$ = 90$^{\circ}$
a$^{\circ}$ = 45$^{\circ}$
