Question

HELP HELP HELP pls pls

Answer 1

Answer:

6

Step-by-step explanation:

$\triangle{PQR}$ is a right triangle.  Use the Pythagorean Theorem:

(leg)^2 + (leg)^2 = (hypotenuse)^2

The length of PR is r + 4; it's the hypotenuse.

$PQ^2+QR^2=PR^2$

$r^2+8^2=(r+4)^2 \\ r^2+64=r^2+8r+16 \\ 64=8r+16 \\ 48=8r \\ 6=r$

Remember, to expand $(r+4)^2$ you multiply $(r+4)(r+4)$