PPT-Isosceles Triangles

Sec 45 Sol G5 Properties of Isosceles Triangles An isosceles triangle is a triangle with two congruent sides The congruent sides are called legs and the third side is called the base 3. Classifying Triangles by Angles. ACUTE. OBTUSE. RIGHT. EQUIANGULAR. ACUTE TRIANGLE. All interior angles are acute (or have a measure less than 90°). Interior Angle. Example of Acute Triangle. Phineas’s. Geometry Module 3-1 Isosceles Right Triangle Reflections Overview: of squares through isosceles right triangles. Objective: TExES Mathematics Competencies III.012.D. The beginning teacher uses proper Sec: 4.6. Sol: G.5. Properties of Isosceles Triangles. An isosceles triangle is a triangle with two congruent sides.. The congruent sides are called legs and the third side is called the base.. 3. Leg. th. Grade. TRIANGLES. Triangles. A polygon with three sides. Is the simplest of the polygons. Formed by three straight lines. The interior angles add up to 180 degrees. Exterior angles add up to 360 degrees.. A. . = . B. . C. . D. . = .  . Warm-Up. ~Write one sentence explaining what answer you chose.. ~Write one sentence explaining what answers you were able to eliminate.. Polygons and Triangles. The word polygon means many (poly) angles (gon). This includes triangles, squares, rectangles, trapezoids, parallelograms, . Triangles. L.E.Q. How do you use and apply properties of isosceles triangles to solve problems. ?. Parts of an Isosceles Triangle. .. Between the 2 legs.. Surround the base.. If 2 sides of a triangle are congruent, then the angles opposite those sides are congruent.. Triangles. Isosceles Triangles. leg. leg. base. Vertex angle. Base angle. Base angle. 2 sides are congruent. 2 theorems. If 2 sides are congruent, then base angles are congruent. If 2 . base angles . and. . 4.2/1-10. Lessons 4.1 and 4.2 . Triangle Sum Properties & Properties of Isosceles Triangles. -. Classify triangles and find measures of their angles.. - Discover the properties of Isosceles Triangles.. Warm Up. 1. . Find each angle measure.. True or False. If false explain.. 2.. Every equilateral triangle is isosceles.. 3.. Every isosceles triangle is equilateral.. . 60°; 60°; 60°. True. False; an isosceles triangle can have only two congruent sides.. Objective. :. To understand and apply properties of isosceles and equilateral triangles.. Supplies. :. Math Notebook. Assignment: 4.8 p. 276: 1-10, 12-16, 22-26. 4.8: Isosceles & Equilateral Triangles. Lewis Carroll/Charles Dodgson. Some . fun facts:. .. as a mathematician, Dodgson was, in the words of . . Peter Heath: "An inveterate publisher of trifles [who] was forever putting out pamphlets, papers, broadsheets, and books on mathematical topics [that] earned him no reputation beyond that of a crotchety, if sometimes amusing, controversialist, a compiler of puzzles and curiosities, and a busy yet ineffective reformer on elementary points of computation and instructional method. In the higher reaches of the subject he made no mark at all, and has left none since." . Recall that an isosceles triangle has at least two congruent sides. The congruent sides are called the . legs. . The . vertex angle. is the angle formed by the legs. The side opposite the vertex angle is called the . Geometry. 5.1 Angles of Triangles. Essential Question. How are the angle measures of a triangle related?. 5.1 Angles of Triangles. November 21, 2016. 5.1 Angles of Triangles. November 21, 2016. Goals – . Geometry. Legs are congruent. Isosceles Triangle. Vertex Angle. Base Angles. Legs. Theorem 4-3 (Isosceles Triangle . Thm. ):. If two sides of a triangle are congruent, then the angles opposite those sides are congruent..