Does the graph represent a function? Why or why not?

Fredrick designed an experiment in which he spun a spinner 20 times and recorded the results of each spin

The radius of the circle is 4 cm and the measure of the central angle is 90° the area of the sector with a central angle measuring 90° and radius of length 4 cm is vt cm the triangle in the sector is 4 cm the area of the triangle is v/cm² the area of the segment of the circle is (471 - ) cm?

How to do this , and can some one explain