which
In plane trigonometry, the sine theorem or also known as the law of sines is a ratio between the lengths of the sides of a triangle and the sines of their corresponding opposite angles.
it is
According to the question Sin A=Sin B, so
wich means that this right traingle has two equal sides
if the two sides of a right triangle have the same length, then, they form the same angle with the hypotenuse
also, the question says that C=90 °
we know the sum of the internal angles on a triangle must be 180 °,then
so the answer is B)45 °