Find the area of the blades of the magnetic compass shown in (Take =

1.	Find the area of the blades of the magnetic compass shown in (Take = 3.32).
Answer» Let a, b and c are the sides of blade and s is the semi-perimeter, then its area is given by: A = \(\sqrt{s(s-a)(s-b)(s-c)}\)where s = \(\frac{a+b+c}2\)[Heron’s Formula] s = \(\frac{a+b+c}2\) = \(\frac{5+5+1}2\) = 5.5 A = \(\sqrt{5.5(5.5-5)(5.5-5)(5.5-1)}\) A = \(\sqrt{5.5\times0.5\times0.5\times4.5}\) = 2.49 cm² Hence, total area of both the blades = 2 × 2.49 = 4.98 cm²

Find the area of the blades of the magnetic compass shown in (Take = 3.32).

Answer»

Let a, b and c are the sides of blade and s is

the semi-perimeter, then its area is given by:

A = \(\sqrt{s(s-a)(s-b)(s-c)}\)where s = \(\frac{a+b+c}2\)[Heron’s Formula]

s = \(\frac{a+b+c}2\) = \(\frac{5+5+1}2\) = 5.5

A = \(\sqrt{5.5(5.5-5)(5.5-5)(5.5-1)}\)

A = \(\sqrt{5.5\times0.5\times0.5\times4.5}\) = 2.49 cm²

Hence, total area of both the blades = 2 × 2.49 = 4.98 cm²