The altitude of the smaller triangle is

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

Write and solve a real word problem that involves determining distance on a coordinate plane

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax