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

The area of a triangle can be obtained by heron's formula.

$$S=\frac{a+b+c}{2}$$

Where S = semiperimeter

a = 35

b = 84

c = 91

So S = $$\frac{35+84+91}{2}$$

= $$\frac{210}{2}$$

= 105

area of a triangle = $$\sqrt{\ S\left(S-a\right)\left(S-b\right)\left(S-c\right)}$$

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

= $$\sqrt{\ 105\times70\times21\times14}$$

= $$\sqrt{2160900\ }$$

= 1470 $$cm^2$$