In rhombus abcd the diagonals ac and bd intersect at e. if ae=5 and be=12 what is the length of ab

Can someone me with the property questions for 12 13 and 14 plz

This is about circle theorems. someone asap : (

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )