Question

find the area of a triangle whose sides are 4cm , 8 cm and perimeter is 20​

Answer 1

Answer:

A≈15.49cm²

a Side

4

cm

b Base

8

cm

P Perimeter

20

cm

Answer 2

Answer:

Area = 4√15 cm²

Step-by-step explanation:

Perimeter of the triangle = a + b + c

=>> a + b + c = 20

=>> 4 + 8 + c = 20

=>> 12 + c = 20

=>> c = 8

Therefore, Third side is 8cm.

By heron's formula,

=>> √s(s - a)(s - b)(s - c)

Here, s is semi-perimeter which would be ½ of 20cm = 10cm.

So, the Area is give by,

=>> √s(s - a)(s - b)(s - c)

=>> √10(10 - 8)(10 - 8)(10 - 4)

=>> √10(2)(2)(6)

=>> √240

=>> 4√15

Area of the triangle is 4√15 cm²