We have been asked to calculate the perimeter of Triangle CDE. We can do this by adding the lengths of all three sides. First, we must find the length of each side using the Distance Formula. Let's being with EC.
The Distance Formula will give us the length of both EC and ED as well.
Side
Coordinates
sqrt((x_2-x_1)^2+(y_2-y_1)^2)
Length
EC
(2,-3) (4,-1)
sqrt(( 4- 2)^2+( -1-( -3))^2)
sqrt(8)
ED
(2,-3) (4,-5)
sqrt(( 4- 2)^2+( -5-( -3))^2)
sqrt(8)
We continue by calculating the length of CD. The points C and D have the same x-coordinate and therefore the segment is vertical. We can calculate its length using the Ruler Postulate.
