Question

the diameter of a coin is 4.2 cm find its surface area

Answer 1

radius = diameter / 2
4.2 / 2 = 2.1
And area = pie radius ^2
area = 22/ 7 2.1 × 2.1 = 4. 41
22/ 7×4.41= 13.26

Answer 2

Answer:

Surface area of coin is 0.0027 m²

Explanation:

It is given that,

Diameter of a coin is 4.2 cm. The radius of coin is equal to its diameter divided by 2. So, radius of coin, r = 2.1 cm = 0.021 m

The space occupied by an object is called its area. Surface area of coin is given by,  $A=2\pi r^2$

$A=2\times 3.14\times 0.021^2$

A = 0.0027 m²

Hence, the surface area of the coin is 0.0027 m²