Presentation on theme: "7-7 6 th grade math Triangles. Objective To classify and draw triangles, and find missing angles in triangles. Why? To further your knowledge in measurement."— Presentation transcript:
Objective To classify and draw triangles, and find missing angles in triangles. Why? To further your knowledge in measurement and geometry and keeping building a strong foundation in MG in HS
California State Standards MG 2.3: Draw … triangles from information about them (e.g., … a right isosceles triangle). AF 1.1 : Write and solve one-step equations in one variable. AF 3.2: Express in symbolic form simple relationships arising from geometry MG 2.0: Identify and describe the properties of two- dimensional figures. MR 2.4: Use a variety of methods, such as words, numbers, symbols, charts, graphs, tables, diagrams, and models, to explain mathematical reasoning.
Vocabulary Triangles – 3 sided figure and the sum of the angles are 180 °. Remember that a triangle is ½ a square or rectangle (whose angles measure 360°). Congruent triangles – Triangles with the same size and shape
Vocabulary Equilateral triangle – A triangle with all three sides congruent Scalene triangle – A triangle with no sides congruent (all 3 sides are different) Isosceles triangle – A triangle with 2 sides congruent sides Right triangle – A triangle with a right angle (only 1 angle is needed)
Vocabulary Acute triangle – A triangle with all three angles with acute measures Obtuse triangle – A triangle with an obtuse angle (only 1 angle is needed) ↓
Classifying Triangles Classified by Sides *Three congruent sides - equilateral triangle *Two congruent sides - isosceles triangle - may be acute, right, or obtuse *No congruent sides - scalene triangle -may be acute, right, or obtuse Classified by Angles *All acute angles - acute triangle - may be equilateral, isosceles, or scalene *One right angle - right triangle - may be isosceles or scalene *One obtuse angle - obtuse triangle -may be isosceles or scalene
How to Find Missing Angles of a Triangle 1) Add the 2 known angles 2) Subtract 180 from Step 1 3) Check work Triangle with known sides 90 ° and 30 °. 90 ° + 30 ° = 120 ° 180 ° – 120 ° = 60 ° 3 rd side = 60 °
Try It! Classify each triangle in 2 ways 1. 2. 3. 4. 1)Scalene, right 2)Isosceles, acute 3)Scalene, obtuse 4)Equilateral, acute
Objective Review To classify and draw triangles, and find missing angles in triangles. Why? You have furthered your knowledge in measurement and geometry and keeping building a strong foundation in MG in HS You can classify and draw triangles according to side and angle measures. By knowing that the sum of the angles of a triangle is 180 °, you can find the measure of an unknown angle.
Independent Practice Complete problems 10- 23 Copy original problem first. Show all work! If time, complete Mixed Review: 24-30 If still more time, work on Accelerated Math.