Let n and m be the sides of the kite
perimeter = 2(m+n)
51 = 2(18+m)
51/2 = 18 + m
25.5 - 18 = m
m = 7.5m
Step-by-step explanation:
y-intercept = 2
x-intercept= 2.5
Vertex= 1,4
y=mx+b
From the setup of the problem, the "length of the top of the bookcase, measured along the attic ceiling" will be the hypotenuse of a right triangle, the length "AB". We have both the angle between AB and AC and the length of AC (3.24 meters), so we can use trigonometric identities.
The cosine of the 40 degree angle between AB and AC is equivalent to the length of AC divided by the length of AB. Equivalently, we have:

where "h", the hypotenuse, is the length we want. Rearranging the formula to solve for h we have that

which is 4.2295... meters. Converting to centimeters (multiplying by 100) we have that h = 422.95... centimeters, or if we round the value, h = 423 centimeters.
8ft by 12ft
the real question is why they randomly switched from metric to standard system. :P
The reciprocal of 3/5 is 5/3.
To get the reciprocal of a fraction, just turn it upside down.
A fraction has a numerator, top number, and a denominator, bottom number.
To get the reciprocal of a fraction, just swap over the numerator and denominator.
If whole numbers, to get the reciprocal of whole number, just divide the whole number by 1 to make it into a fraction, then get the reciprocal of that fraction.