Given: Two concentric circles with AB tangent to smaller circle at R
Prove: AR=RB

b. 2 and 4

step-by-step explanation:

df =

both have same length

for this case we have that by definition, the surface area of a cylinder is given by:

where:

r: it is the radius of the cylinder

h: it is the height of the cylinder

we can also rewrite it as:

where:

la: it's the lateral area

ba: area of the base

option a