The angles of a triangle equal 180, not 360. That means B, C, and D are all eliminated, because all of those formulas when done, the sum of the angles will be over 180 degrees. A is the only answer choice that makes sense. The answer is A.
First work out the number of shelves per bookcase: 65/13 = 5 It is 5 shelves per bookcase. 6 x 5 = 30. Therefore 32 shelves are enough to make 6 bookcases.
