Question

find the area of an isosceles triangle whose equal sides are 12cm and perimeter is 30cm​

Answer 1

Answer:

use herons formula....

Answer 2

Answer:

27√7cm^2 or 71.4cm^2

Step-by-step explanation:

Equal sides = 12cm

perimeter = 30cm

Since, perimeter = Equal sides + third side

Therefore, third side = perimeter - Equal sides

or, third side = (30 - 12)cm

or, third side = 18 cm

We can find the area of the triangle by Herons Formula

Therefore, area = √s(s-a)(s-b)(s-c)

where, a=b=12cm, c=18cm

s=a+b+c/2=21cm

=√21(21-12)(21-12)(21-18)

=√21*9*9*3

=27√7cm^2 or 71.4cm^2