step 1
Find out the measure of angle P
Remember that the sum of the interior angles in any triangle must be equal to 180 degrees
so
P+Q+R=180 degrees
substitute given values
P+70+60=180
P=180-130
P=50 degrees
step 2
Applying the law of sines
QR/sin P=PR/sin 70
substitute given values
QR/ sin 50=5/sin 70
QR=(5/sin 70)*sin 50
the answer is option D
