Challenge the radius of circle a. Circle a has a radius of 6 ft. Circle b has a radius 2 ft greater than circle a. Circle c has a radius 3 ft greater than circle b. Circle d has a radius 1 ft less than circle c. What is the area of each circle? How many times greater than the area of circle a is the area of circle d?
a) Circle a: 36π, Circle d: 36π, 1 time greater
b) Circle a: 36π, Circle d: 9π, 1/4 times greater
c) Circle a: 36π, Circle d: 25π, 25/36 times greater
d) Circle a: 36π, Circle d: 16π, 4/9 times greater