A) Area of circle is 452.16 square inches and circumference of circle is 75.36 inches
B) Area of circle is 490.625 square centimeters and circumference of circle is 78.5 cm
Solution:
The area of circle is given as:

Where "r" is the radius of circle
The circumference of circle is given as:

Where "r" is the radius of circle
a) radius of 12 inches
r = 12 inches
Substitute r = 12 and
in area formula

Thus area of circle is 452.16 square inches
Substitute r = 12 and
in circumference formula

Thus circumference of circle is 75.36 inches
b) diameter of 25 centimeters
diameter = 25 cm
We know that,


Thus radius is 12.5 cm
Substitute r = 12.5 and
in area formula

Thus area of circle is 490.625 square centimeters
Substitute r = 12.5 and
in circumference formula

Thus circumference of circle is 78.5 cm