In ∆ABC, which ratio equals cos C?

Which math sentence can be used to determine if the triangle is a right triangle?

Someone answer asap for ! the total ticket sales for a high school basketball game were $2,260. the ticket price for students were $2.25 less than the adult ticket price. the number of adult tickets sold was 230, and the number of student tickets sold was 180. what was the price of an adult ticket?

Dimitri used a coupon that saved him 80 percent, or $6.87. he paid $34.35 for the items.dimitri used a coupon that saved him 80 percent, or $27.48. he paid $34.35 for the items.dimitri used a coupon that saved him 80 percent, or $6.87. the price of the items before the discount was $34.35.dimitri used a coupon that saved him 80 percent, or $27.48. the price of the items before the discount was $34.35.