Answer:
No, it is not a square
Step-by-step explanation:
If one wall is 19", that would mean the wall perpendicular to this wall is also 19" (in fact all of the walls would be 19"!) If this was a square, then the diagonal we draw at 20.62" would serve as the hypotenuse of a right triangle. One wall would serve as a leg, and another wall as another leg. If this is a square, then the Pythagorean's Theorem would be satisfied when we plug in the 2 wall measures for a and b, and the diagonal for c:

We need to see if this is a true statement. If the left side equals the right side, then the 2 legs of the right triangle are the same length, and the room, then is a square.
361 + 361 = 425.1844
Is this true? Does 722 = 425.1844? Definitely not. That means that the room is not a square.
Slope: 3, y-intercept: 4, equation: y = 3x + 4
A reciprocal is just when you flip over the numerator and the denominator.
So, if you have 5/8, then its opposite, or reciprocal will be 8/5. It is also a fraction, as is 5/8.
You can write it as a mixed number, as the person above me mentioned, as 1 3/5.