Question 344676
Need to know:  Heron's formula for computing Area of Triangle knowing the length of its sides a,b,c  with s being 1/2 the Perimeter of the Triangle.
Area = {{{sqrt(s(s-a)(s-b)(s-c))}}}

Question states the following to be true: Sides are 6, 8, 10
Perimeter of the triangle is 24
s = 12

substituting gives:
Area = {{{sqrt(12*6*4*2))}}}
Area = {{{sqrt(576))}}}
Area = 24

Rectangle B has an equal area with a width of 4
A = w*H
4*H = 24
H = 6
Perimeter of the Rectangle is 2*w + 2*h or in more detail:
4 + 4 + 6 + 6  = 20