What is the area of triangle having sides 35 cm, 84 cm and 91 cm?
Answer & explanation
Correct answer: option 3
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