Loading [MathJax]/jax/output/HTML-CSS/jax.js
Home / Aptitude Tests / Mathematics / Find the area, to th...
Find the area, to the nearest cm2, of the triangle whos...

Find the area, to the nearest cm2, of the triangle whose sides are in the ratio 2 : 3 : 4 and whose perimeter is 180 cm.

A.

1162 cm2

B.

1163 cm2

C.

1160 cm2

D.

1161 cm2

Correct answer is A

Let the length of the sides of triangle be 2x, 3x and 4x.

Perimeter of triangle = 180cm

2x+3x+4x=180

9x=180

x=1809 = 20cm

Then the sides of the triangle are:

2x=2×20=40cm;3x=3×20 = 60cm and 4x = 4×20= 80cm

Using Heron's formula

Area of triangle = s(sa)(sb)(sc)

Where s = a+b+c2

Let a = 40cm, b = 60cm, c = 80cm and s = 40+60+802=1802 = 90cm

⇒ A = 90(9040)(9060)(9080)=90×50×30×10=1350000

∴ A =1162cm2 (to the nearest cm2)