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Today’s Lesson. Determining Angle Measures when Parallel Lines Are Cut by a Transversal. Warm-Up Activity. We will warm up today by finding angle measures. 150°. x. How can you find the missing angle without using a protractor?. These are supplementary angles.
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Today’s Lesson Determining Angle Measures when Parallel Lines Are Cut by a Transversal
Warm-Up Activity We will warm up today by finding angle measures.
150° x How can you find the missing angle without using a protractor? These are supplementary angles. Supplementary angles add up to 180°.
150° x The supplementary angles add up to 180 degrees. x + 150 = 180 x = 180 – 150 x = 30 30°
43° x How can you find the missing angle without using a protractor? x = 43° These angles are vertical. Vertical angles have the same angle measure.
82° x 32° How can you find the missing angle of the triangle without using a protractor? What do you know about triangles that will help you find the missing angle? The sum of the triangle’s angles equals 180 degrees.
82° x 32° The sum of the triangle’s angles equals 180 degrees. 82 + 32 + x = 180 114 + x = 180 x = 180 – 114 x = 66 66°
Whole-Class Skills Lesson Today, you will focus on using patterns to find missing angles.
43° 43° Congruent Angles have the same measure in degrees
Parallel Lines Are always the same distance apart. They will never intersect.
Transversal A line that crosses a pair of parallel lines.
Corresponding Angles 1 2 4 3 A B D C Angles in the same position on parallel lines cut by a transversal are congruent.
Corresponding Angles 1 2 4 3 A B D C
Vertical angles have the same angle measure. The sum of the triangle’s angles equals 180 degrees. Supplementary angles add up to 180 degrees.
c 1 2 a 4 3 5 6 b 8 7 Lines a and b are parallel. What types of angles do you see in this example? Supplementary, Vertical, and Corresponding Angles
c 1 2 a 4 3 5 6 b 8 7 Lines a and b are parallel. Angles 1 and 5 Angles 4 and 8 Angles 2 and 6 Angles 3 and 7 Can you name the corresponding angles?
c 1 2 a 4 3 5 6 b 8 7 Lines a and b are parallel. Angles 1 and 3 Angles 4 and 2 Angles 5 and 7 Angles 6 and 8 Can you name the vertical angles?
c 1 2 a 4 3 5 6 b 8 7 Lines a and b are parallel. Angles 1 and 2 Angles 2 and 3 Angles 3 and 4 Angles 4 and 1 Angles 5 and 6 Angles 6 and 7 Can you name some of the supplementary angles? Angles 7 and 8 Angles 5 and 8
c 110 2 a 4 3 5 6 b 8 7 Lines a and b are parallel. If Angle 1 measures 110 degrees, what is the measure of Angle 3? 110°
c 110 2 a 4 3 5 6 b 8 7 Lines a and b are parallel. If Angle 1 measures 110 degrees, what is the measure of Angle 4? 70°
c 110 2 a 4 3 5 6 b 8 7 Lines a and b are parallel. If Angle 1 measures 110 degrees, what is the measure of Angle 8? 70°
c 110 2 a 4 3 5 6 b 8 7 Lines a and b are parallel. If Angle 1 measures 110 degrees, what is the measure of Angle 7? 110°
c 1 2 a 4 3 5 52° b 8 7 Lines a and b are parallel. If Angle 6 measures 52 degrees, what is the measure of Angle 7? 128°
c 1 2 a 4 3 5 52° b 8 7 Lines a and b are parallel. 128° 52° 52° 128° 128° 52° 128° If Angle 6 measures 52 degrees, what is the measure of all the angles on the diagram?