Let P(1,2,1), Q(1,0,-1), R(2,2,0) be the vertices of a parallelogram with adjacent sides PQ and PR. Find the other vertex S.

Given:

The vertices of a parallelogram are P(1,2,1), Q(1,0,-1), R(2,2,0).

PQ and PR are the adjacent sides of the parallelogram.

To find:

The coordinates of vertex S.

Solution:

We know that, the diagonals of a parallelogram bisect each other.

Let the coordinates of the vertex S are (a,b,c).

In the given parallelogram PS and QR are the diagonals. It means their midpoints are same.

On comparing both sides, we get

Similarly,

And,

Hence, the coordinates of vertex S are (2,0,-2).

the given 6 = w/p is equivalent to 6p = w, where w is the total area of the walls and p is the area covered by a single can of paint.

knowing that 6 cans of paint will be needed, 6p = w becomes 6(6) = w = 36.   this tells us that the total area to be painted is 36 square units.