Pearson Geometry Common Core, 2011
PG
Pearson Geometry Common Core, 2011 View details
7. Midpoint and Distance in the Coordinate Plane
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Exercise 49 Page 55

Practice makes perfect
a AB is the distance between points A and B. To find this distance, let's start by finding the coordinates of the points on the graph.
The coordinate for A is (-2,-2) and the coordinate for B is (8,-6). Now we can use the Distance Formula. d=sqrt((x_2-x_1)^2+(y_2-y_1)^2) Let's substitute our points into this formula and simplify.
d = sqrt((x_2-x_1)^2 + (y_2-y_1)^2)
d=sqrt(( -2- 8)^2+( -2-( -6))^2)
d=sqrt((-2-8)^2+(-2+6)^2)
d=sqrt((-10)^2+4^2)
d=sqrt(100+16)
d=sqrt(116)
d≈10.8
The distance between points A and B is approximately 10.8.
b Now, we want to find the midpoint of line segment AB. We can do this using the Midpoint Formula.
M ( x_1+x_22, y_1+y_22) Let's substitute our points into the formula and simplify.
M(x_1+x_2/2,y_1+y_2/2)
M(8+( -2)/2,-6+( -2)/2)
M(8-2/2,-6-2/2)
M(6/2,-8/2)
M(3,-4)
The midpoint of line segment AB is the point (3,-4).