A spherical tree ornament is to be painted in bright colors. If the ornament has a diameter of 4 cm,
how much paint is needed?
Math - bobpursley, Sunday, October 25, 2009 at 9:27pm
Wouldn't it depend on how well the paint covers area?
Math - michael, Monday, October 26, 2009 at 12:48am
The amount of paint you need is the exact same amount of area the ornament has.
The problem tells you that the ornament is a sphere, so the formula for area is
A = &pid2
since we know d=4cm them we have
A = &pi*(4cm)2
Since A = the amount of paint we found the answer 16cm2
Math - PsyDAG, Monday, October 26, 2009 at 9:37am
In contrast to michael's post, the formula for the surface area of a square is actually
A = 4 (pi)* r^2
Since the diameter is 4, the radius = 2, so
A = 4 (pi) * 4 = 16 (pi) = 16 (3.1416) = ?
I hope this helps a little more. Thanks for asking.