Triangle ABC is rotated 135 degrees about point S to create A’ B’ C’ What is the perimeter of ABC

First question:

4(3x-5) + (2x -2)(4 + 3x-5)
Simplify > 12x - 20 + (2x-2)(3x-1)
Multiply the second part > 12x - 20 + 6x^2 -8x + 2
Combine like terms > 6x^2 + 4x - 18

Each side of the addition sign represents one of the rectangles above which is then added to get the area of the entire figure.

Second question:

The average is the summation of each data value divided by the number of data values. So it would be

(4 + 5 + 9)/ 3

Simplify > 18/3
Divide > 6