Question

In the figure below PQRS is a trapezium with QR parallel to PS.QR=6cm, RS=4cm, QS=9cm and PS=10cm

Calculate

1. The size of angle SQR
2. The area of triangle PQS

Answer 1

1. The size of angle SQR 
   4²=9²+6²-2 x 6 x 9 cosQ
   108cosQ=101
   Q = cos 10.9352
   Q =20.74º
2. The area of triangle PQS 
   area of PQS
   = ½ x 9 x 10 sin 20.740
   = 15.94cm²