210 likes | 295 Views
Transparency 2. Click the mouse button or press the Space Bar to display the answers. Splash Screen. Example 2-3b. Objective. Find missing angle measures in triangles and classify triangles by their angles and sides. Example 2-3b. Vocabulary. Triangle.
E N D
Transparency 2 Click the mouse button or press the Space Bar to display the answers.
Example 2-3b Objective Find missing angle measures in triangles and classify triangles by their angles and sides
Example 2-3b Vocabulary Triangle A figure formed by three line segments that intersect only at their endpoints
Example 2-3b Vocabulary Acute triangle A triangle having three acute angles
Example 2-3b Vocabulary Obtuse triangle A triangle having one obtuse angle
Example 2-3b Vocabulary Right triangle A triangle having one right angle
Example 2-3b Vocabulary Scalene triangle A triangle with no congruent sides
Example 2-3b Vocabulary Isosceles triangle A triangle that has at least two congruent sides
Example 2-3b Vocabulary Equilateral triangle A triangle that has three congruent sides
Lesson 2 Contents Example 1Find a Missing Angle Measure Example 2Classify Triangles Example 3Classify Triangles
Find the value of x in Example 2-1a The sum of the 3 angles of a triangle = 1800 17 17 + 46 17 + 46 + mR 17 + 46 + mR = 180 Write an equation Replace mP with 17 Replace mQ with 46 Define variable as mr Bring down = 180 1/3
Find the value of x in Example 2-1a Combine “like” terms 17 + 46 + mR = 180 Bring down + mR = 180 63 + mR = 180 63 Ask “what is being done to the variable”? The variable is being added by 63 Do the inverse on both sides of the equal sign 1/3
Find the value of x in Example 2-1a Bring down 63 17 + 46 + mR = 180 Subtract 63 63 + mR = 180 63 Bring down + mR = 180 63 63 - 63 63 - 63 + mR = 180 63 - 63 + mR = 180 - 63 Subtract 63 Combine “like” terms 0 0 + mR = 0 + mR = 117 Bring down + mR = Combine “like” terms 1/3
Find the value of x in Example 2-1a Use the Identity Property to add 0 + mR 17 + 46 + mR = 180 63 + mR = 180 63 Add dimensional analysis 63 63 - 63 63 - 63 + mR = 180 63 - 63 + mR = 180 - 63 0 0 + mR = 0 + mR = 117 mR = 117 mR = 1170 Answer: 1/3
Find the value of x in Example 2-1b Answer: m I =350 1/3
Example 2-2a Classify the triangle by its angles and its sides. Angles Right triangle Sides Isosceles triangle B is a right angle Segments AB and BC are congruent Answer: right, isosceles triangle 2/3
Example 2-2b Classify the triangle by its angles and its sides. Answer: acute, equilateral triangle 2/3
Example 2-3a Classify the triangle by its angles and its sides. Angles Obtuse triangle Sides Scalene triangle Q is an obtuse angle No sides are congruent Answer: Obtuse, scalene triangle 3/3
Example 2-3b * Classify the triangle by its angles and its sides. Answer: right, scalene triangle 3/3
End of Lesson 2 Assignment