Question

sides of triangle are in ratio3:4:5 and perimeter is 12cm find area​

Answer 1

Answer:

6cm²

Step-by-step explanation:

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

Answer 2

Answer:

Step-by-step explanation:

let the sides be 3x,4x and 5x.

3x+4x+5x=12

12x=12

x=1

sides: 3x=3cm , 4x=4cm, 5x=5cm

semi-perimeter = 12/2= 6 cm

using herons formula

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

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

root 6*3*2*1

root 36

6 cm^2

HOPE THIS HELPS