Need help with this problem

Two vertices of a polygon are (7, −18) and (7, 18) . what is the length of this side of the polygon? enter your answer in the box. units

Giuseppi's pizza had orders for $931.00 of pizzas. the prices were $21 for a large pizza, 514 for a medium pizza, and $7 for a small pizza. the number of large pizzas was two less than four times the number of medium pizzas. thenumber of small pizzas was three more than three times the number of medium pizzas. how many of each size of pizza were ordered?

Which radical expression is a rational number? a. √ 360 b. √ 644 c. √ 225 d. √ 122