Understanding Spheres and Surface Area

What is the formula for calculating the surface area of a sphere?

• π * r²

• 4 * π * r²

• 2 * π * r²

• 4 * π * r

If the radius of a sphere is 3 cm, what is the approximate surface area?

• 28.3 cm²

• 113.1 cm²

• 56.5 cm²

• 226.2 cm²

Which of the following is true about the constant π?

• It is approximately equal to 3.14.

• It equals exactly 4.

• It is a variable that changes with the radius.

• It is used only in sphere calculations.

Given a sphere with a surface area of 105 cm², what is the approximate radius?

• 3.5 cm

• 2.89 cm

• 1.5 cm

• 4.2 cm

What is the first step in finding the radius of a sphere if the surface area is known?

• Subtract 4π from the surface area.

• Divide the surface area by 4π.

• Square the surface area.

• Multiply the surface area by 4π.