Question

Find the area of the triangle.
20.) The area of a triangle is 216 cm and its sides are in the ratio 3 : 4:5. Find the perimeter
of the triangle​

Answer 1

Let a = 3x cm, b = 4x and c = 5x

Then, s = 6x

A=s(s−a)(s−b)(s−c)−−−−−−−−−−−−−−−−−−√=6x×3x×2x×x−−−−−−−−−−−−−−√=(6x2)cm2∴6x2=216⇒x2=36⇒x=6

So, a = 18 cm, b = 24 cm and c = 30 cm

Perimeter :

= (18 + 24 + 30) cm

= 72 cm

Answer 2

Answer:

Answer:

perimeter=72cm

Given:

• Area of the triangle=216cm².
• And it's sides are in the ratio=3:4:5

To find:

Perimeter of the triangle=?

Solution:

Let us consider the sides are 3x ,4x and 5x

a=3x, b=4x, c=5x

Now,

→S=a+b+c/2

→s=12x/2=6x

Area=216cm²

√s(s-a)(s-b)(s-c)=216

√6x(2x)(3x)(x)=216

√36x⁴=216

6x²=216

x²=36

x=6

So, perimeter=sum of all sides

Perimeter=3x+4x+5x

=12x=12(6)=72cm