I can't figure out how to solve it could someone help me?

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Find the required measurements of the following trapezoids. a = 8 cm b = 16 cm h = 10 cm

Ifurniture stores having a weekend sale and is offering 20% discount on patio chairs and table the sales tax on furniture is 6.25 using function composition how can you represent the total amount a that you would need to pay for this furniture that cost x dollars