Question

GEOMETRY HELP PLEASE

In △PQR, what is the length of QR?

A. 56√3
B. 56√2
C. 28
D. 28√2

Answer 1

use trigonometry
cos 45 = QR/ 56

Answer 2

Could you elaborate a little more sir? im new to Geo.

Answer 3

\[\cos 45 = 1/\sqrt{2}\]
\[\cos \theta = adjacent/hypotenuse\]

Answer 4

the cos of an angle = adjacent / hypotenuse or A / H
see drawing