Question

The formula below can be used to work out the area of any triangle. What

is the area of a triangle with sides of 5, 7 and 8? Give your answer to 2
decimal places.
area of a triangle =
√s (s-a) (s-b) (s-c)
where a, b and care the lengths of the sides
a+b+c
and s=

Answer 1

The semiperimeter, s, is calculated by adding the three sides together and dividing by 2:

s = (5 + 7 + 8) ÷ 2 = 10

Then we can use the formula to calculate the area of the triangle:

area = √s(s-a)(s-b)(s-c) = √10(10-5)(10-7)(10-8) ≈ 17.32

Therefore, the area of the triangle is approximately 17.32 square units, rounded to 2 decimal places.