Ok I need help remember a semi circle is equal to 3.14 I need help if anyone know how to find a area of a composite figure

What is the celsius temperature that is equal to 94 degrees fahrenheit using the formula f=9/5 c+32

Isuck at math ; ^; m a student solved this problem and said the answer is 3 feet. chase had a roll of ribbon that contained 7 7/8  feet of ribbon. he cut off one piece that was 3 5/8  feet long and another piece that was 1 1/4  feet from the roll. how much ribbon was left on the roll? is the student's answer reasonable? yes, the answer is reasonable. no, the answer is not reasonable. it should be about 2 feet. no, the answer is not reasonable. it should be about 13 feet. no, the answer is not reasonable. it should be about 4 feet.

Can you me find the missing length. i attached an image.