Given that ABC is a right triangle.
∠C is a right angle. ∠C = 90° and sin A = sin B
We need to determine the measure of angle A.
Measure of ∠A:
Let the angles of A and B be x.
By triangle sum property, we get;
[tex]\angle A+\angle B+\angle C=180^{\circ}[/tex]
Substituting the values, we get;
[tex]x+x+90=180[/tex]
Adding the terms, we get;
[tex]2x+90=180[/tex]
Simplifying the terms, we have;
[tex]2x=90[/tex]
[tex]x=45[/tex]
Hence, the measure of ∠A = 45° and the measure of ∠B = 45°
Thus, Option B is the correct answer.