Question

The diameter of a coin is 4.2 cm. Find its surface area.
Give the answer with proper solution.
And the right answer is 13.86 cm^2

Answer 1

The answer is not possible because to calculate the surface are of a coin we need both radius and height, but the question only provides us radius.So please recheck your question.

Answer 2

Answer:

yes the correct answer is 13.86 cm².

let us see how .

Explanation:

Area of a circle is =pier²

radius is half of diameter

so if we divide our diameter 4.2/2 then it will be 2.1 cm .

so radius will be 2.1 cm

now we will put our values in the formula

Area = pier²

=22×2.1×2.1

7

now we will multiply 2.1×2.1=4.41

so it will be =22×4.41

7

now divide 4.41 by 7 = 0.63

=22×0.63

answer =13.86 cm²