Question

find the area of the cloth needed if each of the 8 triangular part of an umbrella is 4m,4m,and 2m

Answer 1

Given: Length of the sides of the triangular cloth - 4m, 4m and 2m.

To find: The amount of cloth required.

Answer:

Heron's formula - √s(s - a) (s - b) (s - c)

Let a be 4, b be 4 and c be 2.

a + b + c = Perimeter.

4 + 4 + 2 = 10m

a + b + c/2 = s

10/2 = 5

s = 5

s - a = 5 - 4 = 1m

s - b = 5 - 4 = 1m

s - c = 5 - 2 = 3m

Using the formula, √s(s - a) (s - b) (s - c)

√5*1*1*3

= √15m^2

Therefore for 8 triangular parts,

√15*8 = 8√15m^2

Therefore, 8√15m^2 of cloth is required.

Hope it helps :)