1 / 12

Unit 2

Triangles. Unit 2. Definition of Triangle. A geometric figure formed by three segments joining noncollinear points. B. C. A. Naming Triangles. Triangles are named by using its vertices. For example, we can call the following triangle:. ∆ABC. ∆ACB. ∆BAC. ∆BCA. ∆CAB. ∆CBA.

Download Presentation

Unit 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Triangles Unit 2

  2. Definition of Triangle A geometric figure formed by three segments joining noncollinear points .

  3. B C A Naming Triangles Triangles are named by using its vertices. For example, we can call the following triangle: ∆ABC ∆ACB ∆BAC ∆BCA ∆CAB ∆CBA

  4. Opposite Sides and Angles Opposite Sides: Side opposite to A : Side opposite to B : Side opposite to C : Opposite Angles: Angle opposite to : A Angle opposite to : B Angle opposite to : C

  5. Equilateral: A A B C C BC = 3.55 cm B BC = 5.16 cm G H I HI = 3.70 cm Classifying Triangles by Sides Scalene: A triangle in which all 3 sides are different lengths. AC = 3.47 cm AB = 3.47 cm AB = 3.02 cm AC = 3.15 cm Isosceles: A triangle in which at least 2 sides are equal. • A triangle in which all 3 sides are equal. GI = 3.70 cm GH = 3.70 cm

  6. A triangle in which all 3 angles are less than 90˚. G ° 76 ° ° 57 47 H I A ° 44 ° 108 ° 28 C B Classifying Triangles by Angles Acute: Obtuse: • A triangle in which one and only one angle is greater than 90˚& less than 180˚

  7. Classifying Triangles by Angles Right: • A triangle in which one and only one angle is 90˚ Equiangular: • A triangle in which all 3 angles are the same measure.

  8. polygons triangles scalene isosceles equilateral Classification by Sides with Flow Charts & Venn Diagrams Polygon Triangle Scalene Isosceles Equilateral Lesson 3-1: Triangle Fundamentals

  9. polygons triangles right acute equiangular obtuse Classification by Angles with Flow Charts & Venn Diagrams Polygon Triangle Right Obtuse Acute Equiangular

  10. Helpful Triangle Information Triangle Sum: The sum of the interior angles in a triangle is 180˚. Third Angle of a Triangle: If two angles of one triangle are congruent to two angles of a second triangle, then the third angles of the triangles are congruent. Fact # 1: Each angle in an equiangular triangle is 60˚. Fact # 2: Acute angles in a right triangle are complementary. There can be at most one right or obtuse angle in a triangle. Fact # 3:

  11. Exterior Angle and Remote Interior Angles Exterior Angle - An angle formed by one side of a triangle and the extension of another side of the triangle. Remote Interior Angles – Interior angles that are not adjacent to the exterior angle of the triangle.

  12. Exterior Angle Theorem The measure of the exterior angle of a triangle is equal to the sum of the measures of the remote interior angles. Remote Interior Angles A Exterior Angle Example: Find the mA. B C 3x - 22 = x + 80 3x – x = 80 + 22 2x = 102 mA = x = 51°

More Related