## Trigonometry 7th Edition

B = $45^{\circ}$
In right triangle CDB- Given acute angle C = $45^{\circ}$ and B is also an acute angle. We know that acute angles of a right triangle add up to $90^{\circ}$ Therefore B + C = $90^{\circ}$ B + $45^{\circ}$ = $90^{\circ}$ B = 90 - 45 = $45^{\circ}$