SSC CGL 9 Aug 2015 Shift 1 Paper

Let the sides of triangle be 3x, 4x and 5x units.
Here, ${\left(3\mathit{x}\right)}^2+{\left(4\mathit{x}\right)}^2$ = ${\left(5\mathit{x}\right)}^2$
Hence, it is a right angled triangle.

Area of ΔABC
= $\frac{1}{2}$ × AB × BC
⇒ $\frac{1}{2}$ × 3x × 4x = 7776
⇒ $6{\mathit{x}}^2$ = 7776
⇒ ${\mathit{x}}^2$ = $\frac{7776}{6}$ = 129*6
⇒ x = $\sqrt{1296}$ = 36 cm
= 3x + 4x + 5x
= 12x = 12 × 36 = 432 cm.