A ​2-ft vertical post casts a ​20-in shadow at the same time a nearby cell phone tower casts a 125​-ft shadow. How tall is the cell phone​ tower?

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

How do i do this? i don’t understand

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