1. Bellwork 1.The coordinates of the endpoints of, in the standard (x, y) coordinate plane, are A (2, -4) and B( - 6, 3). What is the y-coordinate of the midpoint of ? 2.What is the intersection of plane TWM and plane QPW ? 3.What is the intersection of and ?

2. 1.3b Missing Endpoints Students will be able to find missing endpoints. Students will be able to find a value for x that would make a point a midpoint.

3. Example 1 B is between A and C. If AB = 3x + 5 and BC = 6x – 2, AC = 21, is B a midpoint?

4. Example 2 If EC = 2x + 8 and CF = 8x – 4, for what value of x is C the midpoint of ?

5. Example 3 On the (x, y) coordinate plane, M(6, -10) is the midpoint of. If the coordinates of A are (2, -4), find the coordinates of B.

6. Example 4 On the (x, y) coordinate plane, R(4, -7) is the midpoint of. If the coordinates of B are (6, -3), find the coordinates of A.

7. Group Work Complete the worksheet in your groups of 4. I will collect one to grade.

8. Homework: Pg. 26 # 12, 28, 30, 40, 50, 66, 72 – 76 evens Quiz Tomorrow over sections 1.1-1.3

9. Problem 1 On the (x, y) coordinate plane, if E(-6,4) is the midpoint of and F has coordinates (-5,-5), what are the coordinates of D?

10. Problem 2 B is between A and C. If AB = 2x + 4 and BC = 3x – 2, for what value of x is B also the midpoint?

11. Problem 3 D is the midpoint of segment. If DE = 6.5, what is EF?

12. Problem 4 M is between P and Q. If MP = x 2 and MQ = 3x and PQ = 18, is M a midpoint?