In an urban project, triangular plots with side ratios 3 : 4 : 5 are allocated. If the perimeter is 60 m, find the area.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 150 m2.
Side length ratio = 3 : 4 : 5
Let the sides are 3k, 4k, and 5k
Perimeter = 3k + 4k + 5k = 12k = 60 ⇒ k = 60/12 = 5
Sides are 3k = 3(5) = 15 m, 4k = 4(5) = 20 m, and 5k = 5(5) = 25 m
Since 152 + 202 = 225 + 400 = 625 = 252, it's a right-angled triangle
Area = (1/2) × 15 × 20 = 150 m2