Question

. .Find the area of an equilateral triangle ofside 3cm.​

Answer 1

Answer:

The Area of an equilateral triangle is 3.89 $cm^{2}$ .

Step-by-step explanation:

Given -

Sides of an equilateral triangle is $3\:cm$ .

To find -

The area of an equilateral triangle

Solution -

Equilateral triangle is a triangle which is having all equal length sides.

As we know that,

Area of an equilateral triangle = $\frac{\sqrt{3} }{4} a^{2}$

Where,

a = side length of equilateral triangle

a =  $3\:cm$

Put the given value in these formula we get

Area of an equilateral triangle = $\frac{\sqrt{3} }{4}\times 3^{2}$

$3^{2} = 3\times3= 9\\\sqrt{3} = 1.73$

Put these value

Area of an equilateral triangle  =  $\frac{1.73}{4} \times9$

Area of an equilateral triangle  = $\frac{1.73\times9}{4}$

Area of an equilateral triangle  = $\frac{15.58}{4}$

By dividing 15.58 by 4 we get

Area of an equilateral triangle  = $3.89\:cm^{2}$

∴ The Area of an equilateral triangle is 3.89 $cm^{2}$ .

Answer 2

In context to question asked,

We have to determine the area of equilateral triangle having side 3 cm.

As we know that,

All the sides of equilateral triangle are equal.

Area of Equilateral triangle $\frac{{\sqrt{3}}}{4}\:side^2$

So for determining the value of area of triangle we will put the value of side given in the question in above formula,

Thus we will get the area of equilateral triangle as,

$\frac{{\sqrt{3}}}{4}\:\times 3^2\\=>\frac{{\sqrt{3}}}{4}\:\times 9\\=\frac{9{\sqrt{3}}}{4}\:cm^2$

Hence, area of the triangle will be $\frac{9{\sqrt{3}}}{4}\:cm^2$