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Chapter 4.1 - Classifying Triangles Objective: To be able to identify and classify triangles by their angles and sides. Check.4.9 Classify triangles, quadrilaterals, and polygons (regular, non-regular, convex and concave) using their properties.
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Chapter 4.1 - Classifying TrianglesObjective: To be able to identify and classify triangles by their angles and sides. Check.4.9 Classify triangles, quadrilaterals, and polygons (regular, non-regular, convex and concave) using their properties. Check.4.10 Identify and apply properties and relationships of special figures (e.g., isosceles and equilateral triangles, family of quadrilaterals, polygons, and solids).
Classifying Triangles Classify by Angles Classify by Sides Scalene Triangle No two sides are the same Isosceles Triangle At least two sides are the same Equilateral Triangle All sides are the same • Acute Triangle • All angles < 90 • Obtuse Triangle • One angle > 90 • Right Triangle • One angle = 90
Classify the Triangles A Right Triangles Acute Triangles ADB EDB ACD ABC DCE BCE ADE AEB C B D ObtuseTriangles E
Classify the Triangles A Equilateral Triangles Isosceles Triangles ADB EDB none AEB AED ACB ACD BCD DCE Scalene Triangles C B D E
Find Missing Values in Triangle Find x and the measure of each side of the Equilateral Triangle RST if RS = x + 9, ST = 2x, and RT = 3x -9 x + 9 = 2x -x -x 9 = x RS = x + 9 = 9 + 9 = 18 S x + 9 2x T R 3x - 9
Find Missing Values in Triangle Find d and the measure of each side of the Equilateral Triangle KLM if KL = d + 2, LM = 12 - d, and KM = 4d -13 d + 2 = 12 - d +d +d 2d + 2 = 12 -2 -2 2d = 10 d = 5 KL = d + 2 = 5 + 2 = 7 L d + 2 12 - d M K 4d -13
Use the distance formula • Find x and the measure of the sides of DEC. Classify the triangle by its sides E(-5, 3) C (3, 9) D (2, 2) C E D • Isosceles Triangle
Use the distance formula • Find x and the measure of the sides of RST. Classify the triangle by its sides R(-1, -3) S (8, -1) T (4, 4) T RS = √85 ST= √41 RT= √74 R S • Scalene Triangle
Practice Assignment • Block Page 239, 16 – 36 Every 4th and 44 • Honors page 239 30 – 52 Even