Question

Three of the four vertices of a rectangle are located at (4, 2), (7, 2) and (4, 8). a. What are the coordinates of the missing vertex? ( , ) b. Find the area and perimeter of the rectangle. Area = square units Perimeter = units

Answer 1

Answer:

a) The coordinates of the missing vertex = (7, 8)

b) Area = 18 square units

   Perimeter = 18 units

Step-by-step explanation:

a) We know three of the four vertices:

A: (4, 2)           C ______ D(?)

B: (7, 2)               |             |

C: (4, 8)           A |______| B  

To find the coordinates of the missing vertex we need to calculate the distance in the x-direction from point A to point B:

$B_{x} - A_{x} = 7 - 4 = 3$                    

Hence, the distance of point D from point C in the x-direction is:

$D_{x} = C_{x} + 3 = 4 + 3 = 7$

Now, to find the coordinate in "y" we need to calculate the distance in the y-direction between point C and point A:

$C_{y} - A_{y} = 8 - 2 = 6$  

Then, the distance of point D from point B in the y-direction is:

$D_{y} = B_{y} + 6 = 2 + 6 = 8$

Therefore, the coordinates of the missing vertex (point D) are:

$D = (D_{x}, D_{y}) = (7, 8)$    

b) The area of the rectangle is:

$a = (B_{x} - A_{x})*(C_{y} - A_{y}) = 3*6 = 18 units^{2}$

The perimeter is given by:

$p = 2*(3 + 6) = 18 units$

I hope it helps you!