Help! Can someone explain how to do this?

20 da is equal to a. 2,000 cm. b. 2 m. c. 20,000 cm. d. 20,000 mm

Asailor is looking at a kite. if he is looking at the kite at an angle of elevation of 36and the distance from the boat to the point where the kite is directly overhead is 40 feet, how high is the kite?

Olga used 100 ounces of flour to make 225 muffins. how many ounces of flour will be used to make 300 muffins?