Lesson 3C.3

Distance and Midpoint formulas (5.1.1)

midpoint

• What is a midpoint?

– A point that is exactly ½ the distance between 2 endpoints.

• Look at the graph below: The endpoints are (-2, -6) and (4, 8). The MIDPOINT is at (1, 1)

midpoint

midpoint

midpoint

Distance

• What is DISTANCE?

– A numerical value for how far two objects are from each other.

• Look at an object 2 feet to your left. Now pick a new object 2 feet to your right. How far is each object from you? Is either distance negative? WHY or WHY NOT?

distance

DISTANCE

DISTANCE

DISTANCE

DISTANCE

• Find the point that is ¼ the distance from the endpoint (-3, 7) of the segment with endpoints (-3, 7) and (5, 9).

DISTANCE • Can we find an easier way to do this? We can combine the

steps together. Remember we will still need to determine if we need to add or subtract the distance each time.

DISTANCE • Let’s try our last example again, using our new

formulas:

• Find the point that is ¼ the distance from the endpoint (-3, 7) of the segment with endpoints (-3, 7) and (5, 9).

DISTANCE

• Find the point that is 4/5 the distance from the endpoint (18, 16) of the segment with endpoints (18, 16) and (8, 6).

Homework!!

• WB: Page 139 #’s 1-10