Start with the Pythagorean theorem{A²+B²=C², A and B are the sides and C is the Hypotenuse/Longest Side.}
2²+4²=C²
4+16=C²
20=C².....{now square root both sides.√}
√20=√C²
4.472= C
P.S.: hope I helped :)
The vertex of the given modulus function is (3,-7).
Given information:
The given modulus function is,

It is required to find the vertex of the given function.
<h3>What is the vertex of a modulus function?</h3>
Modulus function is in the shape of V. The notch of V is the vertex of the function.
The given function can be defined as,

From the above function, it can be concluded that the vertex of the function should be (3,-7). Also shown in the attached image.
See the attached image.
Therefore, the vertex of the given modulus function is (3,-7).
For more details about modulus function, refer to the link:
brainly.com/question/18793028
<h3>
Answer: Choice A</h3>
Explanation:
Each table has x = 10 in it. Plug this value into the given equation.
y = -2x+17
y = -2*10+17
y = -20+17
y = -3
The input x = 10 leads to the output y = -3. Table A shows this in the middle-most row. So that's why choice A is the answer. The other tables have x = 10 lead to y values that aren't -3 (eg: choice D has x = 10 lead to y = 12), so we can rule them out.
So, first, what are the two sides?
let's call then x and y
we know that 2(x+y)=12.5 (that's the distance around)
so that means that x+y=6.25 (I just divided both by 2)
now, x=4y (from "4 times as long as it is wide")
so we can substitute:
x+4x=6.25
5x=6.25
x=1.25
so one side, is 1.25 and the other will be 1.25*4=5
and for the area we multiply the two:
1.25*5=6.25 square kilometers, and this is the answer!