Opener No Opener Today!
Ch 9.3 Complements, Supplements, Midpoints, Perpendiculars
Page 484 Read for me please… 1.Draw a pair of supplementary angles that share a side. 125° 55° Work on #2 & 3 in your groups…3 minutes
More on page 484 Read for me please… 4. Draw a pair of complementary angles that share a side. 57° 33° Work on #5 & 6 in your groups…3 minutes
Page Two angles are both congruent and supplementary. What is the measure of each angle? Show your work and explain your reasoning. x + x = 180 2x = 180 2x ÷ 2 = 180 ÷ 2 x = 90 The measure of each angle is 90° because the two angles are congruent and their measures must have a sum of 180°.
Still on page Two angles are both congruent and complementary. What is the measure of each angle? Show your work and explain your reasoning. x + x = 90 2x = 90 2x ÷ 2 = 90 ÷ 2 x = 45 The measure of each angle is 45° because the two angles are congruent and their measures must have a sum of 90°.
Page 486 Read for me please… 1. Draw line AB and line CD at point E. How many right angles are formed? A B C D E Work on #2 & 3 in your groups…3 minutes
Page 487 You can use tools to construct a perpendicular line through a point on another line. Use B as the center and draw an arc, intersecting at 2 points Open the compass radius, use C & D as centers and draw intersecting arcs above and below the line, label as point E and F Draw a line through E & F. Line EF is perpendicular to line CD 1. Construct a line perpendicular to the given line through point P, following the above directions.
Skip pages 488, 489 & Page 491 Examples of adjacent angles: 1 2 Angle 1 & Angle 2 are adjacent 1 2 Angle 1 and Angle 2 are not adjacent 1. Describe adjacent angles 2 angles are adjacent if they have a common vertex and a common side. Work on #2 & 3 in your groups…3 minutes
Page Is it possible to draw 2 angles that share a side, but do not share a vertex? It is not possible. If 2 angles share a side then since the sides of an angle are rays, the endpoint of the shared ray is the vertex of both angles
Still on page 492 Linear Pairs Read the box for me please… Notice the difference between the linear angles and the non-linear angles. 1. Describe a linear pair of angles. 2 angles are a linear pair if they are adjacent and their non-common sides form a line.
More on page Draw angle 2 so that it forms a linear pair with angle 1. 12
Page Name all of the linear pairs in the figure shown. The linear pairs are: <1 and <4, <1 and <3, <2 and <3, <2 and <4 4. If the angles that form a linear pair are congruent, what can you conclude? If the angles that form a linear pair are congruent, then the intersecting lines, line segments, or rays forming the linear pair are perpendicular.
Page 493 Vertical angles—look at the example 1.Describe vertical angles. Vertical angles are nonadjacent angles formed by 2 intersecting lines. 2. Draw angle 2 so that it forms a vertical angle with angle
Still on page Name all vertical angle pairs in the diagram shown: Angle 1 and angle 2 are vertical angles. Angle 3 and angle 4 are vertical angles. 4. If you measure the angles in #3 what do you notice? The vertical angles are congruent.