Answer:
84 square units.
Step-by-step explanation:
[tex]\sf \boxed{\bf Area = \sqrt{s*(s-a)(s-b)*(s-c)}}[/tex]
Here, a, b and c are the sides of the triangle. s is the semi perimeter.
a = 13
b = 14
c = 15
[tex]\sf s= \dfrac{a+b+c}{2}\\\\ =\dfrac{13+14+15}{2}\\\\=\dfrac{42}{2}\\\\s = 21[/tex]
s -a = 21 - 13 = 8
s -b = 21 - 14 = 7
s - c = 21 - 15 = 6
[tex]\sf Area = \sqrt{21*8*7*6}[/tex]
[tex]= \sqrt{ 7* 3 * 2 * 2 * 2 * 7 * 2 * 3}\\\\=7 * 3 *2*2\\\\= 84 \ square \ units[/tex]