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7-6. Triangles. Course 2. Warm Up. Problem of the Day. Lesson Presentation. 7-6. Triangles. Course 2. Warm Up 1. What is the name of a six-sided figure? 2. What is the definition of an acute angle?
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7-6 Triangles Course 2 Warm Up Problem of the Day Lesson Presentation
7-6 Triangles Course 2 Warm Up 1.What is the name of a six-sided figure? 2. What is the definition of an acute angle? 3. The measure of one angle of two supplementary angles is 32°. What is the measure of the other angle? hexagon an angle that measures less than 90° 148°
7-6 Triangles Course 2 Problem of the Day Use 6 congruent line segments to form 4 equilateral triangles. (Hint:Use toothpicks or other objects to model the segments.) Place the segments so they form a pyramid.
7-6 Triangles Course 2 Learn to classify triangles by their side lengths and angle measures.
7-6 Triangles Course 2 Insert Lesson Title Here Vocabulary scalene triangle isosceles triangle equilateral triangle acute triangle obtuse triangle right triangle
7-6 Triangles Course 2 One way to classify triangles is by the lengths of their sides. Triangles classified by sides A scalene triangle has no congruent sides.
7-6 Triangles Course 2 One way to classify triangles is by the lengths of their sides. Triangles classified by sides An isosceles triangle has at least 2 congruent sides
7-6 Triangles Course 2 One way to classify triangles is by the lengths of their sides. Triangles classified by sides In an equilateral triangle, all of the sides are congruent.
7-6 Triangles Course 2 One way to classify triangles is by the lengths of their sides. Another way is by the measures of their angles. Triangles classified by angles In an acute triangle, all of the angles are acute.
7-6 Triangles Course 2 One way to classify triangles is by the lengths of their sides. Another way is by the measures of their angles. Triangles classified by angles An obtuse trianglehas one obtuse angle.
7-6 Triangles Course 2 One way to classify triangles is by the lengths of their sides. Another way is by the measures of their angles. Triangles classified by angles A right triangle has one right angle.
7-6 Triangles Course 2 Writing Math When classifying a triangle according to its sides and angles, use the word that describes the sides first, and use the word that describes its angles second.
7-6 Triangles Course 2 Additional Example 1A & 1B: Classifying Triangles Classify each triangle according to its sides and angles. 5 ft Two congruent sides A. isosceles 9 ft 9 ft acute Three acute angles This is an isosceles acute triangle. B. scalene No congruent sides right One right angle 24 m 25 m This is a scalene right triangle. 7 m
7-6 Triangles Course 2 Additional Example 1C & 1D: Classifying Triangles Classify each triangle according to its sides and angles. scalene No congruent sides C. acute Three acute angles This is a scalene acute triangle. D. equilateral Three congruent sides acute Three acute angles This is an equilateral acute triangle.
7-6 Triangles Course 2 Insert Lesson Title Here Try This: Example 1A & 1B Classify each triangle according to its sides and angles. 5 ft isosceles Two congruent sides A. 3 ft 3 ft obtuse One obtuse angle This is an isosceles obtuse triangle. Two congruent sides B. isosceles right One right angle This is an isosceles right triangle.
7-6 Triangles Course 2 Insert Lesson Title Here Try This: Example 1C & 1D Classify each triangle according to its sides and angles. scalene No congruent sides C. obtuse One angle exceeding 90° This is a scalene obtuse triangle. scalene D. No congruent sides obtuse One angle exceeding 90° This is a scalene obtuse triangle.
7-6 Triangles Course 2 Additional Example 2: Identifying Triangles Identify the different types of triangles in the figure, and determine how many of each there are. 2 Scalene ABD, BCD 2 Isosceles ACE, ABC Right 2 ABD, BCD 1 Obtuse ACE 1 Acute ABC
7-6 Triangles DJA, JDG HJI, BCD DFE DJA, ADG JDG, JHI, BCD, DEF Course 2 Insert Lesson Title Here Try This: Example 2 Identify the different types of triangles in the figure, and determine how many of each there are. A B I Type How many Name J C D H Isosceles 5 F G E 2 Obtuse Acute 4
7-6 Triangles Course 2 Insert Lesson Title Here Lesson Quiz Classify each triangle according to its side or angle measures. 1. 7ft, 8ft, 12ft 2. 45°, 90°, 45° 3. 12, 9, 12 4. 120°, 20°, 40° 5. Identify the different types of triangles in the figure and determine how many of each there are. scalene right isosceles obtuse 1 isosceles acute triangle, 1 equilateral triangle, 1 scalene right triangle