Example 2: Angles of a Triangle--Sum of Their Measures (1:37)
A SECTION FROM: Discovering Math: Geometry (Grades 6-8)
Knowing the sum of two of the interior angles of a triangle facilitates finding the third angle.
- 6-8Grades 6-8
Example 2: Constructing an Angle Bisector (1:44)
A SECTION FROM: Discovering Math: Geometry (Grades 6-8)
A few construction steps lead to the bisection of an angle.
- 6-8Grades 6-8
Example 1: Properties of a Triangle (2:58)
A SECTION FROM: Discovering Math: Geometry (Grades 6-8)
An equilateral triangle has equal angles. The sum of two of the sides of the triangle are always longer than the third side.
- 6-8Grades 6-8
Example 1: Inductive Reasoning (1:46)
A SECTION FROM: Discovering Math: Problem Solving (Grades 6-8)
Inductive reasoning leads to the conclusion that the sum of the measures of the angles in any triangle is 180 degrees.
- 6-8Grades 6-8
Example 3: Constructing a Perpendicular Bisector (2:08)
A SECTION FROM: Discovering Math: Geometry (Grades 6-8)
A perpendicular bisector is a line or line segment that stands at right angles to another line segment, dividing it into two equal line segments.
- 6-8Grades 6-8
Introduction (1:20)
A SECTION FROM: Discovering Math: Geometry (Grades 6-8)
Mechanical drawings dictate the lines and angles necessary for drawing construction plans in the building industry.
- 6-8Grades 6-8
Insects and Flight (4:40)
A CHAPTER FROM: Size and Scale: Scale of Flight
Tiny flyers, like insects, have to overcome some challenges that birds don’t face. Smaller wings need more energy to move through the air because of air’s viscosity, or stickiness. Insects bend their wings at much greater angles of attack than...
- 6-8Grades 6-8
- Curriculum Explorer
Defining Properties of Triangles (9:00)
A CHAPTER FROM: Discovering Math: Geometry (Grades 6-8)
Triangles have a number of unique properties involving relative side length and angle size. They are among the most stable of shapes.
- 6-8Grades 6-8
Example 3: Special Triangles--Equilateral and Isosceles (1:47)
A SECTION FROM: Discovering Math: Geometry (Grades 6-8)
Types of triangles based on side lengths and angle measurements include equilateral, isosceles, and scalene.
- 6-8Grades 6-8
Measuring the Circumference of the Earth (4:42)
A CHAPTER FROM: Measurement
Eratosthenes calculated the cirumference of the Earth by measuring the angle of the sun at noon. Students replicate this early work.
- 3-8Grades 3-8
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