Which of the following would be a line of reflection that would map ABCD onto itself? Image Description: Square ABCD with C at 1 comma 3, D at 1 comma 1, A at 3 comma 1, and B at 3 comma 3.

Options:
A. y = 1
B. 2x + y = 2
C. x + y = 4
D. x + y = 1

x + y = 4

Step-by-step explanation:

Took the test and got it right.

Sum of Interior Angles = (Number of Sides -2) • 180 degrees

Number of Sides = (Sum of Interior Angles / 180 degrees) + 2

Number of Sides = (1,080 / 180) +2

Number of Sides = 6 + 2

Number of Sides = 8

a) It is an octagon

b) Each interior angle = 1,080 / 8 = 135 degrees

c) Each Exterior Angle = (360 degrees) ÷ (Number of Sides)

Each Exterior Angle = 360/8

Each Exterior Angle = 45 degrees

Source:
http://www.1728.org/polygon.htm