In the diagram above, PQ = 10 cm, PS = 8 cm and ∠PSR is 60

while ∠SRQ is a right angle. Find SR

  • A 14 cm
  • B 14√3 cm
  • C 10 cm
  • D 10√3 cm
jamb 2006mathematics

The correct answer is A. 14 cm

\( \Delta PST \):

\( \cos 60° = \frac{ST}{8} \)

\( ST = 8 \cos 60° \)

\( ST = 8 \cdot \frac{1}{2} = 4 \)

\( TR = 10 \, \text{cm} \, (\text{opposite sides of a rectangle} \, PQRT) \)

\( SR = ST + TR \)

\( SR = 4 + 10 \)

\( SR = 14 \, \text{cm} \)

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