Find the area of the triangle whose sides are 4, 7, and 9.

I am assuming that 4, 7 , and 9 are the length of the
sides of the triangle.

We are given the sides of the
triangle. Then, we will use the following formula.

Area (A)
= sqrt S( S-a) ( S- b) (S-c) such that.

A =
area/

S = perimeter / 2

a, b,
and c are the sides' length.

let us calculate the
perimeter.

We know that the perimeter P = a + b +
c

==> P = 4 + 7 + 9 =
20

==> S = 20/2 =
10

==> A = sqrt 10* ( 10 -4) ( 10 - 7) ( 10
-9)

            = sqrt
10*6*3*1

             = sqrt(180) = 6sqrt5 square
units.

Then the area of the triangle whose
sides 4, 7, and 9 is 6sqrt5 square units.