Question

In △PQR, what is the length of QR? Image posted
21 radical 2
42 radical 2
21
42 radical 3

Answer 1

relative to angle 45, adj/hypotenuse = QR/42

hence cos(45) = QR/42

hence QR = 42*cos(45) = 42 * sqrt(2)/2 = 21*sqrt(2)

Answer 2

Ok I see what you did to get the first answer! Thanks.