1. 1-3 and 1-4 Measuring Segments and Angles

2. Postulate 1-5 Ruler Postulate The point of a line can be put into a one- to-one correspondence with the real number so that the distance between any two points is the absolute value of the difference of the corresponding numbers. AB = | a – b | BA 410

3. Two segments with the same length are congruent. If AB = CD, then AB ≅ CD ≅ means congruent BA 6 BA DC 6 DC

4. Postulate 1-6 Segment Addition Postulate If three points A, B, and C are collinear and B is between A and C, then AB + BC = AC A B C

5. If GJ = 32, find x find GH find HJ If AX = 45, find y find AQ find QX

6. A midpoint of a segment is a point that divides the segment into two congruent segments. ABC B is the midpoint of AC AB  BC M is the midpoint of RT find x find RM find RT

7. An angle  is formed by two rays (called sides of the angle) with the same endpoint (called the vertex of the angle). Angles are measured in degrees. Sides are GC and GA; G is the vertex. Name this angle:  G  3  CGA  AGC

8. Postulate 1-7 Protractor Postulate Let OA and OB be opposite rays in a plane. OA, OB and all the rays with endpoint O that can be drawn on one side of AB can be paired with the real number from 0 to 180 in such a way that: a. OA is paired with 0 and OB is paired with 180 b. If OC is paired with x and OD is paired with y, then m  COD = | x – y | A B D C O

9. Angles can be... Acute: 0 < x < 90 x° Right: x = 90 x° Obtuse: 90 < x < 180 x° Straight: x = 180

10. Postulate 1-8 Angle Addition Postulate If point B is in the interior of  AOC, then m  AOB + m  BOC = m  AOC. If  AOC is a straight angle, then m  AOB + m  BOC = 180.

11. Angles with the same measure are congruent. If m  1 = m  2, then  1   2 Congruent “ curtains ”