Find the perimeter and the area of the polygon with the given vertices. J (1,2), K (7,2), L (7,8), M (1,8) The perimeter is units. The area is square units.

Respuesta :

Answer:

Perimeter = 24 units

Area = 36 units^2

Step-by-step explanation:

Given

[tex]J=(1,2)[/tex]

[tex]K = (7,2)[/tex]

[tex]L = (7,8)[/tex]

[tex]M = (1,8)[/tex]

Required

Calculate the perimeter and the area

Calculating Perimeter:

First, we calculate the distance between each point.

For J and K

[tex]J=(1,2)[/tex]  [tex]K = (7,2)[/tex]

They have the same y value (i.e. 2); So, the distance is the difference between their x values:

[tex]D_1 = |1-7|=|-6| = 6[/tex]

For K and L

[tex]K = (7,2)[/tex]  [tex]L = (7,8)[/tex]

They have the same x value (i.e. 7); So, the distance is the difference between their y values:

[tex]D_2 = |2-8| = |-6| = 6[/tex]

For L and M

[tex]L = (7,8)[/tex]   [tex]M = (1,8)[/tex]

They have the same y value (i.e. 8); So, the distance is the difference between their x values:

[tex]D_3 = |7-1| = |6| = 6[/tex]

For M and J

[tex]J=(1,2)[/tex]   [tex]M = (1,8)[/tex]

They have the same x value (i.e. 1); So, the distance is the difference between their y values:

[tex]D_4 = |2-8| = |-6| = 6[/tex]

So, the perimeter (P) is:

[tex]P = D_1 + D_2 + D_3 + D_4[/tex]

[tex]P = 6 + 6 + 6 + 6[/tex]

[tex]P = 24[/tex]

Calculating the Area

The area is calculated using:

[tex]Area = \frac{1}{2}|(x_1y_2+x_2y_3+x_3y_4+x_4y_1) - (x_2y_1 + x_3y_2+x_4y_3+x_1y_4)|[/tex]

Where:

[tex]J=(1,2)[/tex] -- [tex](x_1,y_1)[/tex]

[tex]K = (7,2)[/tex] -- [tex](x_2,y_2)[/tex]

[tex]L = (7,8)[/tex] -- [tex](x_3,y_3)[/tex]

[tex]M = (1,8)[/tex] -- [tex](x_4,y_4)[/tex]

So, we have:

[tex]Area = \frac{1}{2}|(1*2+7*8+7*8+1*2)-(7*2+7*2+1*8+1*8)|[/tex]

[tex]Area = \frac{1}{2}|(116)-(44)|[/tex]

[tex]Area = \frac{1}{2}|72|[/tex]

[tex]Area = \frac{1}{2}*72[/tex]

[tex]Area = 36[/tex]