Respuesta :

The ratio of their area is 81 : 1.

Step-by-step explanation:

Given,

The perimeter of two equilateral triangles is 9:1

To find the ratio of their areas.

Formula

If each side of a equilateral triangle is a then perimeter = 3a and area = [tex]\frac{\sqrt{3} }{4}[/tex]a²

Now,

Perimeter of the 1st triangle is 9x

So, each side will be 3x

Again,

Perimeter of the 2nd triangle is x

So, each side will be [tex]\frac{x}{3}[/tex]

Now,

Area of the 1st triangle =[tex]\frac{\sqrt{3} }{4}[/tex](3x)²

Area of the 2nd triangle = [tex]\frac{\sqrt{3} }{4}[/tex]([tex]\frac{x}{3}[/tex])²

Hence,

The ratio of their area = [tex]\frac{\sqrt{3} }{4}[/tex](3x)² :  

= 9x² : [tex]\frac{x^{2} }{9}[/tex]

= 81 : 1

Thus the obtained ration of the triangle is 81:1