Question

find the area of triangle 2 sides which are 18cm and 10cm and perimeter 42cm

Answer 1

Answer:

Given, Side a=18cm Side b=10cm   Perimeter=42cm=a+b+c

:. Putting value   42=18+10+c    then42=28+c       42-28=c

14=c

Now,

S=(a+b+c)/2   :. Putting value   S=42/2

S=21

Now according to Heron's formula-

Area of a triangle    =√{s(s-a)(s-b)(s-c)}    :. Putting value   =√{21(21-18)(21-10)(21-14)}

√{21(3)(11)(7)}   =√4851

21√11cm²

Step-by-step explanation: