Mathematics for IGCSE & O level - Using A Calculator (Section 3 - No. 4)
What is the name of the formula for the surface area of a sphere?
$$ A = 4pi r^2 $$
$$ A = 2pi r $$
$$ A = pi r^2 $$
None of the above
解释
The correct formula is $$ A = 4pi r^2 $$.