A triangle has sides with lengths: 1, 5, and 3. How do you find the area of the triangle using Heron's formula?
There is no such triangle, since
Interestingly, if you attempt to apply Heron's formula with such lengths then you will find yourself trying to take the square root of a negative number, hence no Real area...
Then the semiperimeter is defined by the formula:
#sp = (a+b+c)/2 = (1+5+3)/2 = 9/2#
And the area is given by the formula:
#A = sqrt(sp(sp-a)(sp-b)(sp-c))#