How do you use Heron's formula to determine the area of a triangle with sides of that are 4, 6, and 3 units in length?

1 Answer
Apr 27, 2016

#"Area"_triangle~~5.3# sq.units
(see below for use of Heron's formula)

Explanation:

Heron's formula tells us how to calculate the area of a triangle given the lengths of it's three sides.

If (for the general case) the lengths of the three sides are #a, b, and c# and the semi-perimeter is #s=(a+b+c)/2#

Then
#color(white)("XXX")"Area"_triangle=sqrt(s(s-a)(s-b)(s-c))#

For the given triangle with sides #4, 6, and 3#
#color(white)("XXX")s=13/2#
and
#color(white)("XXX")"Area"_triangle = sqrt((13/2)(13/2-4)(13/2-6)(13/2-3))#

#color(white)("XXXXXXX")=sqrt(13/2xx5/2xx1/2xx7/2)#

#color(white)("XXXXXXX")=sqrt(455)/4#

#color(white)("XXXXXXX")~~5.3# sq.units