Can someone please help me with this problem...thanks

What other information do you need to prove triangle dac=bca by asa

I’m still confused on how to work the percentages

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! )