Question

In AABC, m LACB 90°, CD I AB and m LACD -45°. Find:

Find CD, if BC = 3 in
459
B В
D

Answer 1

CD = (3√2)/2 = 2.12 in.

Explanation:

Reference angle = m<BCD = 45°

Hypotenuse = BC = 3 in.

Adjacent side = CD = ??

Apply trigonometric ratio

Cos(45) = CD/3

Multiply both sides by 3

3*Cos(45) = CD

3*√2/2 = CD (cos 45 = √2/2)

(3√2)/2 = CD

CD = (3√2)/2 = 2.12