Which number is more -79 or -86

Two sides of a triangle mesure 20cm and 30cm. what is the measure of the third side

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 .

Which undefined geometric term is described as a location on a coordinate plane that is designed by an ordered pair (x,y) ?