Answer: 15
<u>Step-by-step explanation:</u>
small: 5 12 13
middle: __ 36 39
large: 45 108 117
Notice that to get from the small to the large, multiplied by 9
5(9) = 45 12(9) = 108 13(9) = 117
That is because the sides are proportional 
To get from small to middle, multiply by 3
5(3) = 15 12(3) = 36 13(3) = 39
To solve it using proportions:
Answer:
science makes you understand the world understand the living organisms understand electricity and understand chemical reactions which is one of the most important things to know in life
Take half of the coefficient of x: It is 3, and half that is 3/2.
Then <span>x^2+3x=6 becomes:
</span><span> x^2+3x + (3/2)^2 =6 + (3/2)^2, and
(x+3/2)^2 = 6 + 9/4
You were not asked to solve the equation, but why not do it for the practice?
</span>Solve (x+3/2)^2 = 6 + 9/4 for x. There will be 2 values.
(4 feet wide), 12 feet in length. 4*3=12 4*12=48
