The sides of a right-angled triangular park are in the ratio 5 : 12 : 13. If the sum of all sides is 120 meters. What is the area…
Basic Numeracy ·Previously asked in JKPSC Combined Competitive Examination (JKCCE) 2025
View the full solved paper: JKCCE Prelims 2025 - GS Paper II (Set B)
Question
The sides of a right-angled triangular park are in the ratio 5 : 12 : 13. If the sum of all sides is 120 meters.
What is the area of the park?
- A. 520 m²
- B. 480 m² (Correct answer)
- C. 120 m²
- D. 360 m²
Correct Answer
Option B — 480 m²
Detailed Solution & Explanation
The correct answer is 480 m².
Key Points
- The sides are in the ratio 5 : 12 : 13, a total of 30 parts.
- The perimeter is 120 m, so one part = 120 ÷ 30 = 4 m, giving sides of 20 m, 48 m and 52 m.
- Since 5-12-13 is a Pythagorean triple, the legs are 20 and 48 and the hypotenuse is 52.
- Area = ½ × 20 × 48 = 480 m².
Additional Information
- Verify the right angle: 20² + 48² = 400 + 2304 = 2704 = 52² ✓
- In any right triangle the two legs serve directly as base and height, so no separate altitude calculation is needed.
*Ministry of Papers worked solution. The Commission has not yet published the official key for this paper; this answer will be reconciled with it on release.*
Topics covered: Mensuration Worked Solution