PPT-Angles of Triangles

Section 42 Objectives Find angle measures in triangles Key Vocabulary Corollary Exterior angles Interior angles Theorems 41 Triangle Sum Theorem Corollary to the Triangle Sum Theorem 42 Exterior Angle Theorem. 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. a. What appears to be true about the lengths of the three tower braces that form a triangle?. b. It also appears that the three angles of the triangles formed by the braces are congruent. If this is true, what is the measure of each of the angles?. TOPIC/Objective: . To use angles to tell whether triangles are similar. . Essential Question: . How can you use angles to tell if triangles are similar. . Example:. . The triangles have two pairs of congruent angles..   ARE THEY SIMILAR. ?. Erica . thinks the triangles at right might be similar.  She asks for your help.  The two triangles are drawn to scale.. If two shapes are similar, what must be true about their angles and sides?. Ms. Andrejko. Vocabulary. Included side-. the side located between two consecutive interior angles of a polygon. Real-World. Postulates/Theorems/Corollaries. P 4.3:. If two angles and the included side of one triangle are congruent to two angles and the included side of another triangle, then the triangles are congruent. 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, . Helpful websites. http://www.regentsprep.org/Regents/mathb/1c/preprooftriangles.htm. http://www.mathwarehouse.com/geometry/congruent_triangles/. http://www.cliffsnotes.com/WileyCDA/CliffsReviewTopic/Congruent-Triangles.topicArticleId-18851,articleId-18788.html. What is a polygon?. Closed figure. At least 3 sides. Line segments are sides. Sides meet is call a vertex. More Polygon Terms. Diagonal – connects two non consecutive vertices. Concave – at least one diagonal outside polygon, dented in. Protractor: . What do you notice? . Task One: . Look at the protractor. Write down everything that you notice about the protractor. Try and come up with at least . 10 facts. Think about . number patterns . They are shapes with all straight sides. You’ve got triangles and squares. You’ve got . rhombuses . and hexagons. Just know that circles are not there.. I want to talk parallelograms!. They’ve got 2 pairs of parallel sides. They are shapes with all straight sides. You’ve got triangles and squares. You’ve got . rhombuses . and hexagons. Just know that circles are not there.. I want to talk parallelograms!. They’ve got 2 pairs of parallel sides. Objectives:. Find the measures of interior and exterior angles of triangles.. Apply theorems about the interior and exterior angles of triangles.. Supplies: Math Notebook. Textbook. Assignment: p. 228 #15-23(skip 17), 29-32. 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 – . Chapter 4. This Slideshow was developed to accompany the textbook. Larson Geometry. By Larson. , R., Boswell, L., . Kanold. , T. D., & Stiff, L. . 2011 . Holt . McDougal. Some examples and diagrams are taken from the textbook..