8.3 - Constructing Perpendicular Bisectors

Focus......Use a variety of methods to construct perpendicular bisectors of Line segments Bisect means to cut in half. When you bisect a line....you cut it in half. If you construct the bisector at right angles (90 degrees) to the line segment.....you've constructed a Perpendicular Bisector. There are several ways to construct perpendicular bisectors: a) Use paper folding. b) Use a compass. c) Use a mira. d) Use a ruler. Method 1 - Paper Folding 1. Draw a line segment AB (about 10cm) 2. Fold the line in half so that Point B is on top of point A. 3. Draw a line down the crease in your paper. This is your perpendicular bisector. Method #2 - Mira 1. Draw a line segment AB (10cm) 2. Place the mira in the middle of the line segment, the reflection of Point A should be on top of Point B (otherwise your line won't be straight). 3. Draw a line down the mira Method #3 - Use a Compass... Method #4 - Ruler 1.) Draw a line segment AB (10 cm) 2.) Place the ruler on a diagonal so that A is on one side of the ruler and B is on the other side. 3.) Draw a line segment down each side of the ruler. 4.) Turn the ruler so that A and B are on opposite sides of the ruler and draw line segments again. 5.) Label the points where the line segments meet, Point "C" and Point "D". 6.) Connect C and D to create a new line segment. CD is perpendicular to AB. Homework: pg. 308-309 # 1-7