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The sides of a triangle are in the ratio 3 : 4 : 5 and its perimeter is 60 cm. The area of the triangle is
A96 sq cm
B150 sq cm
C120 sq cm
D60 sq cm
Answer & Solution
Correct answer: C. 120 sq cm
1. Sides are 3k, 4k, 5k with 12k = 60, so k = 5. Sides: 15, 20, 25 cm.
2. 3 : 4 : 5 indicates a right triangle (15 squared + 20 squared = 625 = 25 squared).
3. Area = 1/2 × 15 × 20 = 150 sq cm.
_Source: NCERT Class 10 Mathematics, Ch 6 "Triangles", §6.5_
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