Ijust need with this
if fe measures 20 meters, the approximate area of circle b is what?
if be measures three point five centimeters, the approximate area of circle b is what?
if ab measures eleven feet, the approximate area of circle b is what
if ef measures twelve meters, the approximate area of circle b is what?

If FE measures 20 meters, the approximate area of circle B is 314 m²

if be measures three point five centimeters, the approximate area of circle B is  38.47 cm²

If AB measures eleven feet, the approximate area of circle B is 379.94 feet²

If EF measures twelve meters, the approximate area of circle B is 113.04 meters²

The image in the attached image is a circle. A circle is a bounded figure which points from its center to its circumference is equidistant.

Area of a circle : πr²

Where

π = pi = 3.14

r = radius. A radius is half of a diameter

Area when FE measures 20 meters

FE is the diameter of the circle. In order to determine the radius, divide the diameter by 2

Radius = 20 /2 = 10 meters

Area = 3.14 x 10² = 314 m²

Area when BE is 3.5 cm

BE is the radius

Area = 3.14 x 3.5² = 38.47 cm²

Area when AB is 11 feet

AB is the radius of the circle

Area = 3.14 x 11² = 379.94 feet²

Area when EF is 12 meters

EF is the diameter. The radius of the circle can be determined by dividing the diameter by 2

Radius = 12 / 2 = 6 meters

Area = 3.14 x 6² = 113.04 meters²

To learn more about the area of a circle, please check: link

The formula for area of a circle is: πr^2

r is half the diameter.

FE is the diameter: r = 20/2 = 10

Area of circle using FE = π10^2 = π * 100 = 314 square meters.

BE is a radius:

Area = π3.5^2 = π * 12.25 = 38.465  = 38.5 square cm ( rounded to nearest tenth).

AB is a radius:

Area = π11^2 = π * 121 = 379.94 = 380 square feet ( rounded off).

EF is a diameter

r = 12/2 = 6 meters

Area = π6^2 = π * 36 = 113.04 = 113 square meters ( rounded off).