Lesson 4:

Triangles

Objectives:

1.  The student will define the following terms:

            triangle
            right triangle
            acute triangle
            obtuse triangle
            equilateral triangle
            isosceles triangle
            scalene triangle

2.  The student will classify angles based on their angle measures and side lengths.

3.  The student will make the following conclusions:

            The sum of the measures of the interior angles of a triangle is 180 degrees.
            For any triangle, the longest side is opposite the largest angle, and the shortest side is opposite the smallest angle.
            Base angles of an isosceles triangle are congruent.
            Interior angles of an equilateral triangle are congruent and are 60 degrees.

Notes

Paper Activity:  Angles of a Triangle

Activity:  Sides of a Triangle

GSP Activity:  Sides of Triangles