How do you use Heron's formula to determine the area of a triangle with sides of that are 7, 15, and 9 units in length?

1 Answer
Feb 13, 2016

Area ~~43.3943.39 sq. units.

Explanation:

Heron's formula tells us that the area of a triangle with sides a, b, and ca,b,andc is
color(white)("XXX")"Area"_triangle=sqrt(s(s-a)(s-b)(s-c))XXXArea=s(sa)(sb)(sc)
where ss is the semi-perimter ((a+b+c)/2a+b+c2).

In this case we have
color(white)("XXX")a=7 color(white)("XX")b=15 color(white)("XX")c=9 and color(white)("XX")s=31/2XXXa=7XXb=15XXc=9andXXs=312

So
Area"_triangle = sqrt(31/2xx17/2xx1/2xx13/2)Area=312×172×12×132

color(white)("XXXX")~~41.39XXXX41.39