Geometry 5.1 Name That Triangle!

Why do you think road signs tend to be different? Would it matter if the signs were irregular? Does the shape make it easier to recognize?

5.1 Classifying Triangles on the Coordinate Plane  Objectives  Determine the coordinates of a third vertex of a triangle, given the coordinates of two vertices and a description of the triangle  Classify a triangle given the locations of its vertices on a coordinate plane

First: Some Review Ideas  What does it mean for a triangle to be a Right Triangle?  The triangle has 1 right angle (the other two are acute)  What does it mean for a triangle to be an Acute Triangle?  The triangle has 1 acute angle (the other two are acute)  What does it mean for a triangle to be an Obtuse Triangle?  The triangle has 1 obtuse angle (the other two are acute)

First: Some Review Ideas  What does it mean for a triangle to be a Scalene Triangle?  No sides are congruent  What does it mean for a triangle to be an Isosceles Triangle?  The triangle has at least 2 sides congruent  What does it mean for a triangle to be an Equilateral Triangle?  All sides are congruent

Problem 1 Location, Location, Location!  Collaborate 1-3 (7 Minutes)

Problem 1 Location, Location, Location!  #2 a: Right Triangle (-2, 7)(-10, 7) (-2, 3) (-10, 3)

Problem 1 Location, Location, Location!  #2 b: Acute Triangle There are many solutions In Circle A, the y- value must be below y=7 In Circle B, the y- value must be above y=3

Problem 1 Location, Location, Location!  #2 c: Obtuse Triangle There are many solutions In Circle A, the y- value must be above y=7 In Circle B, the y- value must be below y=3

Problem 1 Location, Location, Location!  #3 a: Equilateral Triangle The point of intersection between the circles is the same distance from both centers

Problem 1 Location, Location, Location!  #3 b: Isosceles Triangle There are many solutions We just need two sides congruent

Problem 1 Location, Location, Location!  #3 c: Scalene Triangle We just need no sides congruent Cannot have a scalene triangle because at lease two sides are radii of either circle All radii of any circle are congruent

Problem 2: What’s Your Name Again?

Pythagorean Theorem Hint  We can tell what type of triangle, using angles, by the relationship of the sides.

Formative Assessment  Skills Practice 5.1  Pg (7-18)