120 likes | 528 Views
3.4 Constructing Angle Bisectors. Objectives: I CAN discover methods of constructing an angle bisector. I CAN explore how to construct special angles by dividing and combining 60o and 90o angles. Serra - Discovering Geometry Chapter 3: Using Tools of Geometry. Sketch, Draw, Construct.
E N D
3.4 Constructing Angle Bisectors Objectives: I CAN discover methods of constructing an angle bisector. I CAN explore how to construct special angles by dividing and combining 60o and 90o angles. Serra - Discovering Geometry Chapter 3: Using Tools of Geometry
Sketch, Draw, Construct draw When you ___________ an equilateral triangle, you should use you geometry tools for accuracy. You may use a protractor to measure angles and a ruler to measure the sides. When you ___________ an equilateral triangle, you freehand a triangle that looks like an equilateral triangle. No geometry tools needed. When you ___________ an equilateral triangle with a compass and straightedge, you don’t rely on measurements from a protractor or a ruler. This guarantees that you triangle is equilateral. sketch construct Serra - Discovering Geometry Chapter 3: Using Tools of Geometry
P. 158 Investigation Draw an angle. Find a method for constructing the bisector of the angle.
Investigations 1 & 2: p.157-158 Constructing Angle Bisector C8 Angle Bisector Conjecture If a point is on the bisector of an angle, then it is ______________ from the sides of the angle. equidistant Serra - Discovering Geometry Chapter 3: Using Tools of Geometry
Bisecting an Angle Serra - Discovering Geometry Chapter 3: Using Tools of Geometry
Construction 6: Angle Bisector • Draw a large angle on your paper and label it PQR. • With the point of the compass on Q, stretch out the compass as far as you like and make an arc across the entire angle. • Put the point of the compass on the first intersection and make an arc inside the angle. • Without changing the compass, put the point on the other intersection and make another arc inside the angle. You should now have an X. • Connect the vertex and the X with a ray. Mark the congruencies. P Q R 1 2 4 3 http://www.mathopenref.com/constbisectangle.html Serra - Discovering Geometry Chapter 3: Using Tools of Geometry
Match each geometric construction with its diagram. Serra - Discovering Geometry Chapter 3: Using Tools of Geometry
Construct a figure with the given specifications Serra - Discovering Geometry Chapter 3: Using Tools of Geometry