Question

find the length of the side of an equilateral triangle whose perimeter is 21 cm​

Answer 1

Answer:

7cm

Step-by-step explanation:

equilateral traingle has all sides equal,therefore let the side be =a

ATQ

a+a+a=21cm

3a = 21cm

a=7cm

Answer 2

Answer:

Hence the length of a side of an equilateral triangle is 7cm.

Step-by-step explanation:

According to the information provided in the question.

It is stated in the preceding question that,

The presented information is perimeter of an equilateral triangle is 21 cm.

We need to find the side of equilateral triangle.

The formula of perimeter of the equilateral triangle is as bellow,

$P=3a$

Where a is the side of the triangle,

So, the side of the triangle will be,

$3a=P\\a=\frac{P}{3}$

Substitute the value of perimeter in the above equation we get,

$a=\frac{21}{3}$

Dividing both numerator and denominator with 3 we get,

$a=\frac{7}{1}\\a=7cm$

Hence the length of a side of an equilateral triangle is 7cm.