Question

Find area of triangle in which :

1) a = b = c = 4cm (equilateral triangle) .

Answer 1

Answer:

Step-by-step explanation:

s= a + b+ c/2

 = 4 + 4+ 4/2

 = 12/2 = 6 cm

By Heron's formula,

area = √s(s-a)(s-b)(s-c)

        = √6 x (6-4)(6-4)(6-4)

       = √6 x 2 x 2 x 2

      = √3 x 2 x 2 x 2 x 2

      = 2 x 2√3

     = 4√3 sq. cm

Answer 2

Answer:

4√3 sq. cm

Step-by-step explanation:

Side1=Side2=Side3=4cm

(It is an equilateral triangle because the sides are equal)

We can find the area by using heron's formula,

First, find the semi perimeter as given below:

s= a + b+ c/2

s= 4 + 4+ 4/2  

s= 12/2 = 6 cm

Now we find area:

A=$\sqrt{s(s-a)(s-b)(s-c)}$

A=$\sqrt{6(6-4)(6-4)(6-4)}$

A=$\sqrt{6(2)(2)(2)}$

A=$\sqrt{(3)(2)(2)(2)(2)}$

∴A=$4\sqrt{3}$sq.cm