Find the perimeter of ABCD:

Question

Find the perimeter of the polygon formed when these points connect:

A (1,2)

B (1,1)

C (8,1)

D (8,2

Perimeter = __ units

Answer 1

Perimeter equals the sum of the lengths of all the sides. We have the 4 coordinates of the points on the edge of the polygon in (X,Y) format. Graphing it out can help us get a feel for what it will look like and the shape we are working with as well.

In this case we have a rectangle so we need to add up sides AB, BC, CD and AD.

To find the distance between two points on the same line (not diagonally), we subtract the Xs and the Ys)

AB = 1 (1,2)-(1,1)= (0,1) in distance so we know the length is 1 along the Y axis

BC = 7 (8,1)-(1,1)= (7,0) in distance so we know the length is 7 along the X axis

We repeat for CD and AD to get 1 and 7 respectively and add them all up to get our perimeter.

In this case, 7+1+7+1

Cheers

Answer 2

try plotting the 4 points. They form a rectangle with sides 7 by 1

Perimeter - 2(L+W) = 2(7+1) = 2(8) = 16