Answer:
r = 6
Step-by-step explanation:
To get the value of r we will use the pythagoras theorem a shown;
PR² = QR² + PQ²
(4+r)² = 8² + r²
Expand
16+8r+r² = 64 + r²
16 + 8r = 64
8r = 64 - 16
8r = 48
r = 48/8
Hence the value of r is 6
