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Aim:. C. B. A. D. P. 2) Which of the following shapes are polygons ?. c). b). a). e). f). d). What are polygons? How do we classify triangles?. Do Now:. All angles and all sides of a regular polygon are equal in measure.
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Aim: C B A D P 2) Which of the following shapes are polygons? c) b) a) e) f) d) What are polygons? How do we classify triangles? Do Now: Geometry Lesson: Polygons, Triangles
All angles and all sides of a regular polygon are equal in measure. A polygon is a closed figure that is the union of line segments that intersect only at their endpoints. Def: Polygons Def: Regular Polygons: Geometry Lesson: Polygons, Triangles
P R Q Triangles: A triangle is a polygon with exactly three sides. Geometry Lesson: Polygons, Triangles
P R Q “Included” Sides and Angles of Triangles Two angles that share a side “include” the side. Two sides “include” the angle between them. Geometry Lesson: Polygons, Triangles
P R Q “Opposite” Sides and Angles of Triangles Each angle of a triangle has an opposite side, and vice versa. Geometry Lesson: Polygons, Triangles
Def: An triangle has three congruent sides. Def: An triangle has at least two congruent sides. Def: A triangle has no congruent sides. Classifying Triangles by Sides: Equilateral Isosceles Scalene Geometry Lesson: Polygons, Triangles
Legs. Base. Base Angles. Vertex Angle. B C vertex P C A What type of triangle is ? Q E D leg leg ABCDE is a regular pentagon base angle base angle R B A base Isosceles Triangle: 1) The 2 congruent sides are known as . 2) The non-congruent side is the . 3) Angles opposite the legs are the . 4) The angle included by the legs is the . Geometry Lesson: Polygons, Triangles
Classifying Triangles According to Angles: Def: A triangle having three acute angles is an triangle. Acute Triangle. Def: A triangle having three congruent angles is an triangle. Equiangular Triangle. Def: A triangle having a right angle is a triangle Right Triangle. Def: A triangle having an obtuse angle is an triangle Obtuse Triangle. Geometry Lesson: Polygons, Triangles
Hypotenuse. Legs. hypotenuse c leg a leg b Right Triangles: 1) The side opposite the right angle is the . 2) The sides opposite the acute angles are . Hypotenuse. 3) The longest side is the . 4) Pythagorean Theorem: Example: A triangle has sides measuring 9, 12, and 14 cm. Show that this triangle is not a right triangle. Geometry Lesson: Polygons, Triangles