440 likes | 447 Views
Geometry Chapter 2 Learning Targets! By the unit of the chapter, you should be able to:. L.T. #1: Be able to identify angle pairs (corresponding, alternate interior, same-side interior, alternate exterior, same-side exterior)!. Section 1 ~ Parallel and Skew lines!. Quick Definitions:
E N D
Geometry Chapter 2 Learning Targets! By the unit of the chapter, you should be able to:
L.T. #1: Be able to identify angle pairs (corresponding, alternate interior, same-side interior, alternate exterior, same-side exterior)! Section 1 ~Parallel and Skew lines! Quick Definitions: Parallel lines: Parallel planes: Skew lines:
A transversal is a _____ that intersects two other ______! In this picture, line ____ is the transversal. 1 2 3 4 n 5 This transversal creates ____ angles! 6 7 8 m t Pairs of these angles have special names, depending on their positions.
n c a b k m s t p r Identify the transversal(s) in each picture:
Special Angle Pairs in Parallel Lines Cut by a Transversal: Angle Pair: Picture: Relationship:
10 9 11 2 1 12 3 4 6 5 7 8 Practice Identifying the Special Angle Pairs:
10 9 11 2 1 12 3 4 6 5 7 8 Use the picture to complete each statement: If m5 = 130, then m8 =____ because they are… If m4 = 125, then m6 =____ because they are… If m4 = 125, then m8 =____ because they are… If m2 = 45, then m7 =____ because they are… If m3 = 50, then m6 =____ because they are… If m7 = 42, then m1 =____ because they are…
10 9 11 2 1 12 3 4 6 5 7 8 MORE PRACTICE:Use the picture to complete each statement. If m5 = 130, then m4 =____ because they are… If m5 = 25, then m3 =____ because they are… If m5 = 125, then m1 =____ because they are… If m1 = 50, then m8 =____ because they are… If m3 = 50, then m2 =____ because they are… If m2 = 51, then m8 =____ because they are…
2x 2x + 60 3x - 20 x + 60 Find the value of each variable.
Your Turn! 60° 3y
L.T.: Be able to determine relationships between specific pairs of angles and use algebra to find specific angle measurements. 3x 2x + 50 Section 3.2 ~Angles and Parallel Lines Quick Review: Find the value of x and the measure of each angle. Justify each step!
Postulate: When lines are parallel, corresponding angles are ____! Theorem: When lines are parallel, alternate interior angles are ____! Theorem: When lines are parallel, consecutive interior angles are _________! Theorem: When lines are parallel, alternate exterior angles are _________! Theorem: When lines are parallel, consecutive exterior angles are _________!
1 2 3 4 5 6 7 8 Let’s use our theorems to find angle measures If find the following angles and state the theorem used.
10 9 11 2 1 12 3 4 6 5 7 8 Using the picture at the left, find the measure of each angle and tell which postulate or theorem you used. m 1 = m 2 = m 3 = m 4 = m 5 = m 6 = m 7 =
Find the value of the variables in each picture. Explain your answer. 75° 3n -15 ° 13 - x 68 +10x
1 2 3 4 5 6 7 8 Write a 2 column proof to solve for y.Given: m 4 = m 5 = Try this!
L.T.: Be able to prove lines are parallel using the properties of the special angle pairs Section 3.5 ~ Proving Line are Parallel Quick Review: Find the value of x and justify each step. Find each angle measure. 5x -25 3x + 45
90° 90° 45° 37° 37° 89° 45° Converse of Corresponding Angle Postulate: If two lines and a transversal form CORRESPONDING angles that are CONGRUENT, then the two lines are ________________! Where are there parallel lines in the pictures?
50° 100° 100° 130° Converse of Alternating Interior Angle Theorem: If two lines and a transversal form ALTERNATING INTERIOR angles that are CONGRUENT, then the two lines are ________________! Where are there parallel lines in the pictures?
75° 70° 80° 110° 100° 115° Converse of Consecutive Interior Angle Thm: If two lines and a transversal form CONSECUTIVE INTERIOR angles that are SUPPLEMENTARY, then the two lines are ________________! Where are there parallel lines in the pictures?
Converse of ALTERNATE EXTERIOR Angle Thm: If two lines and a transversal form ALTERNATE EXTERIOR angles that are CONGRUENT, then the two lines are ________________! Solve for x so the lines m and n are // x +116 m n 6x - 24
10 9 11 2 1 12 3 4 14 13 16 6 15 5 7 8 Given the following information, is it possible to prove that any of the lines shown are parallel? If so state the postulate or theorem that justifies your answer. t • 2 = 8 • 12 + 13 = 180 • 4 = 6 • 14 = 15 9 = 13 v r s
80° 2x + 40 2x - 30 4x - 40° Find the value of the variable that would make the lines parallel. State which postulate or theorem justifies your answer.
Two More Theorems: Theorem: If two lines are parallel to the same line, then they are parallel to each other! Theorem: If two lines are perpendicular to the same line, then they are parallel to each other!
Let’strya proof! A B 1 2 3 C D
50° 50° Last one, YOUR TURN … Are the lines parallel? Explain.
3.3 Slope and rate of change Objective: We are going to find the rate of change and determine the slope of a line. What does each of the following look like? Positive Slope Negative Slope Zero Slope Undefined Slope
How to find Slope…Anyone remember? When given 2 points (x1, y1) and (x2, y2) plug them into our slope formula:
Try these Ex 3: Find the slope of the line that passes through (9, –3) and (2, 7). Ex 2: Find the slope of the line that passes through (–1, 4) and (1, –2).
Find the slope of the line that passes through the following points. Ex. 4: (2, 3) and (2, 6) Ex. 5: (-5, 7) and (4, 7)
From a graph! Find the slope of the line. Blue Line: Red Line:
Rate of Change COLLEGE ADMISSIONS In 2004, 56,878 students applied to UCLA. In 2006, 60,291 students applied. Find the rate of change in the number of students applying for admission from 2004 to 2006. X – independent variable Y – Dependent variable Wait!
Let’s try One More Find the rate of change for the data in the table.
Parallel and Perpendicular Lines If 2 lines are parallel, there slopes are __________ If 2 lines are perpendicular, there slopes are _________ If m=-4 what is the slope of a line perpendicular and parallel to the line? // m = _____ m = ______ What about if m = ? // m = _____ m = ______
More Parallel and Perpendicular lines Determine whether and are parallel, perpendicular, or neither for the given set of points. Ex 1: A(1, -3) B(-2, -1) C(5, 0) and D(6, 3) Ex 2: A(3, 6) B(-9, 2) C(5, 4) and D(2, 3)
L.T.#1: Be able to graph lines from equations in slope-intercept form! L.T.#2: Be able to write the equation of a line using point-slope form! Section 3.4 ~ Equations of Lines! Recall: Coordinate pairs: (x1, y1) and (x2, y2) SLOPE of a line: Example: Find the slope of the line that passes through (4, 5) and (-1, 2).
Slope-Intercept Form: y = m x + b
Write the equation of the graph shown: Let’s practice s’more!
Point-Slope Form: y = m (x – x1) + y1 Write an equation of a line that passes through (2, -3) and has a slope of –4. Write an equation of a line that passes through (-3, 4) and has a slope of 2/3. Write your final answer in slope-intercept form.
Write an equation of a line that passes through (-2, -1) and (3, 0). Write an equation of a line that passes through (1, 5) and (4, 2). Write your final answer in slope-intercept form.
Write an equation of a line that passes through (-1, 4) and has a slope of 3. Write an equation of a line that passes through (4, -9) and (-1, 1). Write your final answer in slope-intercept form.
One Last thing… Do we know how to graph horizontal and vertical lines??? y = # Graph of a ______________ line x = # Graph of a ______________ line What is the equation Graph y = 2 Graph x = -3 of the line?_______