Question

How many square inches greater is the area of a 30-inch circular mirror than an 18-inch circular mirror?

Answer 1

Answer:

Area of a 30-inch circular mirror is greater than area of a 18-inch circular mirror by 452.16 square inches.

Step-by-step explanation:

We are given the following in the question:

Mirror 1:

$d_1 = 30\text{ inches}\\\\\Rightaroow r_1 = \dfrac{30}{2}=15\text{ inches}$

Area of mirror 1 = Area of circle

$A_1 = \pi r_1^2$

Putting values, we get,

$A_1 = 3.14\times (15)^2=706.5\text{ square inches}$

Mirror 2:

$d_1 = 18\text{ inches}\\\\\Rightaroow r = \dfrac{18}{2}=9\text{ inches}$

Area of mirror 1 = Area of circle

$A_2 = \pi r_2^2$

Putting values, we get,

$A_2 = 3.14\times (9)^2=254.34\text{ square inches}$

Difference between area =

$=A_1-A_2\\=706.5-254.34\\=452.16\text{ square inches}$

Thus, area of a 30-inch circular mirror is greater than area of a 18-inch circular mirror by 452.16 square inches.