(1/7) / (1/5) please review steps

In the surface area formula for cylinders which expressionrepresents the lateral area

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?

Problem melissa is her dad build a walkway in their backyard. the walkway will be 54 feet long and 1.5 feet wide. the local hardware store sells tiles which are 1.5 by 1.5 feet and come in boxes of 12. how many boxes of tiles do they need?