What is the area of triangle having sides 35 cm, 84 cm and 91 cm?

1470 cm²

The three sides of a triangle are = 35cm, 84cm and 91cm.

Let the sides of triangle = a, b and c

Semi perimeter = \(\frac{a + b + c}{2}\)

Semi perimeter= \(\frac{35 + 84 + 91}{2}\) = 105

Area of a triangle = \(\sqrt {s(s-a)(s-b)(s-c) }\)

= \(\sqrt {105(105-35)(105-84)(105-91) }\) 

= \(\sqrt {105(70)(21)(14) }\)

= \(\sqrt {2160900}\)  = 1470