I neeed help with middle school math

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

Which one ? is the answer and how to find this answer

Find measure angle 1 and measure angle 3 in the kite the diagram is not drawn on the scale