Answer:
a, b, c, & d
Step-by-step explanation:
It is D because it means supplementary angles which equal up to 180
Since the diagram is a square and squares have equal sides, you set the the equations equal to each other because they'd have the same measurement.
6x - 1 = 4x + 6
Subtract 4x from each side.
2x - 1 = 6
Add 1 to each side.
2x = 7
Divide by 2 to isolate the variable.
x = 7/2
Now plug this in to either equation to find the length of the side.
6(7/2) - 1 = 21 - 1 = 19 cm.
