Question

the sides of a triangle are in the ratio 3:4:5 and its perimeter is 12 cm find its area ?​

Answer 1

3x + 4x + 5x = 12cm

12x = 12

x = 1

3x = 3cm = a

4x = 4cm = b

5x = 5cm = c

area = √s (s-a) (s-b) (s-c)

where, s = a+b+c / 2

s = 3+4+5/2 = 6

area = √ 6 (6-3) (6-4) (6-5)

= √ 6 × 3 × 2

= √ 36

= 6cm²

HOPE THIS HELPS !!!

Answer 2

Answer:

Let the sides be 3x,4x and 5x

perimeter = sum of sides

12 = 3x + 4x + 5x

12 = 12x

x =1

then, sides are 3 , 4 and 5.

àrea of triangle =

semi perimeter = a + b+ c / 2

= 3+4+5/2

= 12/2 = 6

Heron's formula,

root s (s-a) (s-b) (s-c)

= root 6 (6-3)(6-4)(6-5)

=root 6×3×2×1

=root 36

= 6cm²

hope it helps...