what process can you add groups of three or more integers and how can you confirm that you arrived at the correct total​

in geometry, parallel lines are lines in a plane which do not meet; that is, two lines in a plane that do not intersect or touch each other at any point are said to be parallel. by extension, a line and a plane, or two planes, in three-dimensional euclidean space that do not share a point are said to be parallel.

the answer is  

c.

90.0π cm^2

hope you got it.