The perimeter and the area of a right-angled triangle are 36 cm and 54 square cm respectively. What is the length of the hypotenuse?

  1. A. 12 cm
  2. B. 14 cm
  3. C. 15 cm
  4. D. 16 cm

Correct Answer: C. 15 cm

Explanation

Perimeter p+b+h = 36. Area \frac{1}{2}pb = 54 \implies pb=108. Using p^2+b^2=h^2, we write (p+b)^2 - 2pb = h^2 \implies (36-h)^2 - 216 = h^2. Expanding gives 1296 - 72h = 216 \implies 72h = 1080 \implies h=15 cm.

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