Answer:
4
Step-by-step explanation:
The perimeter of each square window is 4 times the length of one side, so is 20 feet.
80 feet can be divided into 80/20 = 4 sections of 20 feet each.
Shelly has enough lights to surround 4 windows.
Answer:
Step-by-step explanation:

Subtract 4 times the first equation from the second:
(-7y +16x -80) -4(-9y +4x -20) = (0) -4(0)
29y = 0 . . . . . simplify
y = 0 . . . . . . . .divide by 29
4x -20 = 0 . . . . substitute 0 for y in the first equation
x -5 = 0 . . . . . .divide by 4
x = 5 . . . . . . . . add 5
The solution to this system is (x, y) = (5, 0).
The answer would be C. ADB:310 degrees.
A major arc includes 3 points. So that eliminates answer choices B and D.
Angle ACB is a central angle and intercepts the arc AB. The measure of the central angle and the arc it intersects have the same measure. Meaning that Arc AB equals to 50 degrees.
A circle is equal to 360 degrees. So subtract the measure of the minor arc to 360 to get the measure of the major arc.
360-50=310.
Making arc ADB equal 310 degrees