2nd question :) please help quick

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

Which function has the vertex at (2,6)

According to the diagram, an 8-foot-tall statue cast a shadow on the ground that is 15 feet in length. based on the information, which trigonometric ratio has the value 8/15