Question 21
Triangles and QuadrilateralsIn the diagram below, |QR| = 12cm and |QS| = 10cm. If ∠PRQ = 90°, ∠RSQ = 90° and PSQ is a straight line, find |PS|

- A.3.3cm
- B.4.4cm
- C.5cm
- D.5.5cm
- E.6.6cm
Show the answer and explanation
Answer: B (4.4cm)
Explanation
In right triangle RSQ, RS2 = 122 − 102 = 44. In a right triangle the altitude to the hypotenuse gives RS2 = PS × QS, so PS = 44/10 = 4.4 cm.