You can use the Pythagorean theorem to answer this. The diagonal is the hypotenuse of the right triangle that is formed. So, your equation will look like (h is height):

We have to solve for h:


You can plug it into a calculator, and you get approximately 19.105. The answer closest to that is
B. So, that's your answer! Hope it helps. If anything doesn't make sense, hmu!
The correct answer is:
C. They are similar because the corresponding sides of kites KELY and BRAD all have the relationship 2:1.
Using the distance formula,

the lengths of the sides of BRAD are:

The lengths of the sides of KELY are:

Each side of KELY is twice the length of the corresponding side on BRAD. This makes the ratio of the sides 2:1 and the figures are similar.
The difference of two squares factoring pattern states that a difference of two squares can be factored as follows:

So, whenever you recognize the two terms of a subtraction to be two squares, you can factor it as the sum of the roots multiplied by the difference of the roots.
In this case, the squares are obvious:
is the square of
, and
is the square of 
So, we can factor the expression as
![(x+2)^2 - (y+2)^2 = [(x+2)+(y+2)] - [(x+2)+(y+2)]](https://tex.z-dn.net/?f=%20%28x%2B2%29%5E2%20-%20%28y%2B2%29%5E2%20%3D%20%5B%28x%2B2%29%2B%28y%2B2%29%5D%20-%20%5B%28x%2B2%29%2B%28y%2B2%29%5D%20)
(the round parenthesis aren't necessary, I used them only to make clear the two terms)
We can simplify the expression summing like terms:
![(x+2)^2 - (y+2)^2 = [(x+2)+(y+2)][(x+2)-(y+2)] = (x+y+4)(x-y)](https://tex.z-dn.net/?f=%28x%2B2%29%5E2%20-%20%28y%2B2%29%5E2%20%3D%20%5B%28x%2B2%29%2B%28y%2B2%29%5D%5B%28x%2B2%29-%28y%2B2%29%5D%20%3D%20%28x%2By%2B4%29%28x-y%29%20)
Answer:
4.91 is the answer
Explanation:
4.908 the hundredths place is the 0, and 8 is greater than 5, so it would become 4.91