Can someone explain how to do this for like 20 points??

Suppose a pendulum is l meters long. the time,t,in seconds that it tales to swing back and forth once is given by t=2.01

Select the correct answer from each drop-down menu. a system of equations and its solution are given below. system a complete the sentences to explain what steps were followed to obtain the system of equations below. system b to get system b, the equation in system a was replaced by the sum of that equation and times the equation. the solution to system b the same as the solution to system a.]

Use the irregular polygon below. show all work. a. find the perimeter. b. find the area. the angles of the irregular polygon is 2, 8, 8, and 4.