The vertices of a quadrilateral in the coordinate plane are known. how can the perimeter of the figure be found?

a. use the distance formula to find the length of each side, and then add the lengths.
b. use the slope formula to find the slope of each of side, and then determine if the opposite sides are parallel.
c. use the slope formula to find the slope of each of side, and then determine if the consecutive sides are perpendicular.
d. use the distance formula to find the length of the sides, and then multiply two of the side lengths.

(A)

Step-by-step explanation:

We know that perimeter of any quadrilateral is the sum of all the sides. In order to get the perimeter, we should know all the sides of the quadrilateral, thus all the sides can be determined by using the distance formula and then after getting the length of each of the side, add those sides to get the perimeter.

Therefore, to get the perimeter of the given quadrilateral, Use the distance formula to find the length of each side, and then add the lengths.

i used to know how to do this in 7th but i forget easily

step-by-step explanation:

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