1. 1.7
Basic
Constructions

2. You will learn how to construct a line segment, duplicate an angle, and bisect a line segment

3. Construction #1 Use a straightedge to draw a line.
Construct a segment congruent to a given segment.
Given: A B
Use a straightedge to draw a line.
Construct: A1 B1 = AB A1
Now label the point A1 somewhere on the new line.

4. Construction #1
Construct a segment congruent to a given segment.
Set your compass for radius AB and make a mark on the line where B lies.
Given: A B
Construct: A1 B1 = AB l A1 A1 B1
Then, move your compass to line and set your pointer on A1. Make a mark on the line and label it B1.

5. Construction #2 Use a straightedge to draw a ray. Now make an arc.
Construct a angle congruent to a given angle.
Use a straightedge to draw a ray.
Now make an arc.
Make the same arc on the ray.

6. Connect the endpoint and the intersection
Construction #2
Construct a angle congruent to a given angle.
Make another arc
Repeat the arc.
Connect the endpoint and the intersection

7. Construction #3 Make an arc more than half way.
Bisect a line segment with a perpendicular line.
Make an arc more than half way.
Connect the intersection
Repeat the arc on the other side.

8. Connect the vertex with the intersection
Construction #4
Bisect an angle with an angle bisector.
Make an arc.
Make another arc.
Repeat the arc.
Connect the vertex with the intersection

9. Assignment

10. 1.7 Basic Constructions Geometry Construct each figure as directed.
1. Construct AB congruent to XY.
2. Construct the perpendicular bisector of XY.
3. Construct the angle bisector of Z.
4. Construct a triangle whose sides are all the same length as XY. X Y Z
5. Construct AB so that AB = MN + OP
6. Construct KL so that KL = OP - MN
7. Construct A so that mA = m1 + m2
8. Construct C so that C = 2m2
9. Construct the angle bisector of X M N O P 1 2 X