SSC GD 2023 PYQ — Question 53

SSC GD Constable (English) - 12 Jan 2023 - Shift 4 • Quantitative Aptitude • Q53

A triangle has two equal sides, and the third side is 1.5 times any of these sides. If the  perimeter of the triangle is 14 units, then the area of the triangle is ________ square units.

Show answer & explanation

Correct answer: B

Explanation

The correct answer is Option 2 i.e. 3√7.

Let a, b, and c be the sides of the triangle

a = b = x and c = 1.5x

We know that, 

Perimeter = Sum of all sides

14 = x + x + 1.5x

14 = 2x + 1.5x

14 = 3.5x

x = 4

So, a = b = 4 and c = 6

By Heron's Formulae

s = (a + b + c)/2 where s = semi-perimeter

s = (4 + 4 + 6)/2 = 14/2 = 7

Area = s(s−a)(s−b)(s−c)\sqrt{s(s-a)(s -b)(s-c)}

Area = 7(7−4)(7−4)(7−6)\sqrt{7(7-4)(7 -4)(7-6)}

Area = 7×3×3×1\sqrt{7\times3\times3\times1}

The area of the triangle = 373\sqrt{7}