How do you use Heron's formula to find the area of a triangle with sides of lengths #23 #, #21 #, and #7 #?

1 Answer
May 22, 2018

Area of triangle #color(green)(A_t = 72.85# sq units

Explanation:

Given : #a = 23, b = 21, c = 7#

Heron’s formula for area of triangle

#A_t = sqrt(s (s-a) (s-b) (s-c))# where

Semi perimeter #s = (a + b + c) / 2#

#s = (23 + 21 + 7)/2 = 25.5#

#A_t = sqrt(25.5 * (25.5-23) * (25.5-21) * (25.5-7))#

Area of triangle #color(green)(A_t = 72.85# sq units