1. Warm up a)State if the following angles are adjacent angles. b)Explain why or why not 1)∠ AXB and ∠ BXD 2) ∠ AXD and ∠ AXB 3)∠ AXB and ∠ CXE 4)∠ AXC and ∠ CXE A B C D E X

2. 4.3 Constructions

3. For these constructions, first watch me model the construction then we will go through the steps again as you do a construction. Make all markings very light and make your arcs short. Make sure lead is sharp. You may use sand paper to sharpen the lead. If you make a mistake either erase fully or start over. DO NOT SCRIBBLE OUT YOUR MISTAKES!!

4. #1 Construction Construct a congruent line segment. 1)Draw 1)Draw a ray. 2)Open 2)Open compass to the length of original line segment. 3)Place 3)Place point on the vertex of your ray, make an arc on the ray.

5. #1 Construction Construct a line segment that is congruent to a segment that is 3 inches long. So first you must draw a segment that is 3 inches long. 1)Draw 1)Draw a ray. 2)Open 2)Open compass to the length of original line segment. 3)Place 3)Place point on the vertex of your ray, make an arc on the ray.

6. #2 Construction Construct segment bisector. 1)Place 1)Place point of compass on an endpoint of the line segment. 2)Open 2)Open compass so that it is open well beyond where the bisector of the segment should be. 3)Make 3)Make slight arc marks above and below the line segment approximately above and below where the bisector of the segment should be. 4)Pick 4)Pick up compass and without changing the opening of your compass, repeat step 3. 5)Connect 5)Connect the two intersecting point to form the bisector of the line segment.

7. #2 Construction Construct a segment bisector of a line segment 3 inches long. So first you must draw a segment that is 3 inches long. 1)Place 1)Place point of compass on an endpoint of the line segment. 2)Open 2)Open compass so that it is open well beyond where the bisector of the segment should be. 3)Make 3)Make slight arc marks above and below the line segment approximately above and below where the bisector of the segment should be. 4)Pick 4)Pick up compass and without changing the opening of your compass, repeat step 3. 5)Connect 5)Connect the two intersecting point to form the bisector of the line segment.

8. #3 Construction Construct an angle bisector. 1)Place 1)Place point of compass on the vertex of the angle. 2)Open 2)Open the compass to any length and mark both rays of the angle with a slight arc. 3)Move 3)Move point of compass to the intersection of the new arc and the ray, make an arc in the interior of the angle. 4)Move 4)Move point of the compass to the second intersection of the arc and ray and make an arc in the interior of the angle. 5)Draw 5)Draw a ray whose vertex is the vertex of the angle and that passes through the intersection of the arcs in the interior of the angle.

9. #3 Construction Construct a bisector of an angle whose measure is 60°. So first you must draw an angle that has an angle measure of 60°. 1)Place 1)Place point of compass on the vertex of the angle. 2)Open 2)Open the compass to any length and mark both rays of the angle with a slight arc. 3)Move 3)Move point of compass to the intersection of the new arc and the ray, make an arc in the interior of the angle. 4)Move 4)Move point of the compass to the second intersection of the arc and ray and make an arc in the interior of the angle. 5)Draw 5)Draw a ray whose vertex is the vertex of the angle and that passes through the intersection of the arcs in the interior of the angle.