Find the length of a side of a square with an area of 20 ft^2.

The formula for the area of a square is:

A = s²

Area = side²

We know that area (A) is 20 ft²

20 = s²

Now we must find the length of the side (s). To do this we must get rid of the square. To remove the square from s take the square root of both sides:

√20 = √s²

s ≈ 4.5 ft <<< approximate answer

To find the exact answer you must simplify the square root:

s = 2√5 ft <<< exact answer

Each side of the square is exactly 2√5 or approximately 4.5

Hope this helped! Let me know if you have any further questions

~Just a girl in love with Shawn Mendes  

the value of v.w= -12.

step-by-step explanation:

we are given three vector r,v and w as:

r = < 5, -5, -2> ; v = < 2, -8, -8> ; w = < -2, 6, -5>

we know that r,v and w could also be represented as:

r=5i-5j-2k

v=2i-8j-8k

and w= -2i+6j-5k

where i,j and k are the unit vectors of x,y and z-axis respectively.

also we know that it has the following property:

i.i=1 ; j.j=1; k.k=1

and i.=j.i=i.k=k.i=j.k=k.j=0

i.e. when we multiply two vectors or we find it's dot product we need to only multiply the components of x coordinates with each other; y with each other and z with each other.

hence, v.w= (2i-8j- -2i+6j-5k)

                  = 2×(-2)+(-8)×(6)+(-8)×(-5)

                  = -4-48+40

                  = -12

hence, v.w= -12