The area of the base of a prism is 21 cm2. the perimeter of the base is 20 cm. the height of the prism is 8 cm.. what is the surface area of the prism? .

Plz answer asap! i will reward brainliest and 12 points for these three questions!take notice: these three questions are completely different! 1) what is the percentage of sugar in the syrup made of 10 kg of water and 4 kg of suugar? 2) what was the original price if after 10% discount it became $450? 3) at first a price was decreased by 12%, then it was disounted again by an additional 5%. what is the percent of the total discount? , and remeber i will award brainliest and 12 points!

The two cones below are similar. what is the height of the smaller cone?

Mary and roberto bought identical backpacks at different stores. mary's backpack originally cost $65 and was discounted 25%. roberto's backpack originally cost $75 and was on sale for 30% off on the original price. which backpack was the better buy?