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!
Vertex form is basically commplete the square
y=a(x-h)^2+k
y=x^2+14x+4
take 1/2 of 14 and square it, (7^2=49)
add that and its negative to right side
y=x^2+14x+49-49+4
factor perfect squaer
y=(x+7)^2-49+4
y=(x+7)^2-45
answer is A
I think the answer is:
Rectangle: X X O X X
Rhombus: X X X X O
Square: X X X X X
I hope you got a good grade!!!
Not sure what form you want this in:
Simplified this is 4x+4y
Factorised this is 4(x+y)