PQRS is a parallelogram, PX ⊥ SR and RY ⊥ PS. If PQ = 21 cm, PX = 8 cm and RY = 12 cm, find PS.

Correct option is A

Given:

PQ = 21 cm

PX = 8 cm

RY = 12 cm

Concept Used:

Area of parallelogram = base × height

Area calculated using PQ and PX = Area calculated using PS and RY

Solution: 

Area of Parallelogram = PQ × PX = PS × RY

Thus, 

PQ × PX = PS × RY

21 × 8 = PS × 12

168 = PS × 12

PS = $$\frac{168}{12}$$​ = 14 cm