Math 6 Chapter 2 Lesson 9: Triangles 1. Summary of theory Tóm 1.1. What is triangle ABC? Define: Triangle ABC is a figure consisting of three line segments AB; BC; CA when three points A; B; C is not collinear. Sign: The triangle ABC is denoted by \(\Delta ABC\). We also call the name and symbol of the triangle ABC as \(\Delta \)BCA, … [Read more...] about Math 6 Chapter 2 Lesson 9: Triangles

# Math Lesson 6

## Math 6 Chapter 2 Lesson 8: Circles

Math 6 Chapter 2 Lesson 8: Circles 1. Summary of theory Tóm 1.1. Circles and circles A circle with center O, radius r, denoted (O; r) is a figure consisting of points r at a distance from point O. For example: Circle with center O and radius OM = 1.7 cm. Attention: For every point in the plane, then: If ON < R, then point N is inside the circle … [Read more...] about Math 6 Chapter 2 Lesson 8: Circles

## Math 6 Chapter 2 Lesson 7: Practice measuring angles on the ground

Math 6 Chapter 2 Lesson 7: Practice measuring angles on the ground 1. Summary of theory Tóm 1.1. Angle measuring instrument on the ground - Measure the angle on the ground with a trigonometer (figure below) - Structure of the trigonometry: A circular disc is placed horizontally on a tripod. On the top of the disc there is a rotating rod that … [Read more...] about Math 6 Chapter 2 Lesson 7: Practice measuring angles on the ground

## Math 6 Chapter 2 Lesson 6: Bisector of angle

Math 6 Chapter 2 Lesson 6: Bisector of angle 1. Summary of theory Tóm The bisector of an angle is the ray that lies between the two sides of the angle and forms two equal angles with that side. - Ray Oz is the bisector of angle xOt, then: Oz ray lies between two rays Ox, Oy. \(\widehat {xOy} = \widehat {zOy}\) Or \(\widehat {xOz} = \widehat {zOy} … [Read more...] about Math 6 Chapter 2 Lesson 6: Bisector of angle

## Math 6 Chapter 2 Lesson 5: Draw an angle that gives the measure

Math 6 Chapter 2 Lesson 5: Draw an angle that gives the measure 1. Summary of theory Tóm Given an Ox ray, how to draw the angle \(\widehat {xOy}=m^0\) with \(0< m < 180\): - Place the protractor so that the center of the ruler coincides with the angle O of the Ox ray and the Ox ray passes through the 0 . lineo - Draw an Oy ray across the m . lineo of the … [Read more...] about Math 6 Chapter 2 Lesson 5: Draw an angle that gives the measure

## Math 6 Chapter 2 Lesson 4: When is angle xOy + angle yOz= angle xOz?

Math 6 Chapter 2 Lesson 4: When is angle xOy + angle yOz= angle xOz? 1. Summary of theory Tóm 1.1. When is the sum of the measures of two angles xOy and yOz equal to the measure of the angle xOz? If the ray Oy lies between the two rays Ox and Oz then \(\widehat {xOy}\,\, + \,\widehat {yOz\,}\, = \,\widehat {xOz}\) Conversely, if \(\widehat {xOy}\,\, … [Read more...] about Math 6 Chapter 2 Lesson 4: When is angle xOy + angle yOz= angle xOz?

## Math 6 Chapter 2 Lesson 3: Angle measure

Math 6 Chapter 2 Lesson 3: Angle measure 1. Summary of theory Tóm 1.1. Protractors - Each angle has a measure. The measure of a flat angle is \({180^0}\) - The measure of each angle does not exceed \({180^0}\) 1.2. Compare two angles We compare two angles by comparing their measures. - Two angles are congruent if their measures are … [Read more...] about Math 6 Chapter 2 Lesson 3: Angle measure

## Math 6 Chapter 2 Lesson 2: Angle

Math 6 Chapter 2 Lesson 2: Angle 1. Summary of theory Tóm - Corner is a figure consisting of two rays with a common origin. The common origin of two rays is called the vertex of the angle. The two rays are the two sides of the angle. - Sign: \(\widehat {xOy};\,\,\,\widehat {yOx};\,\,\,\widehat O\) - Flat angle is an angle whose sides are opposite … [Read more...] about Math 6 Chapter 2 Lesson 2: Angle

## Math 6 Chapter 2 Lesson 1: Half plane

Math 6 Chapter 2 Lesson 1: Half plane 1. Summary of theory Tóm 1.1. Half plane a) Flat surface - A table top, a table top, a spread sheet of paper... give us an image of the plane. - The plane is not constrained in all directions. b) Half plane - The figure consisting of the line a and the part of the plane divided by a is called the half plane of … [Read more...] about Math 6 Chapter 2 Lesson 1: Half plane

## Math 6 Chapter 1 Lesson 10: Midpoint of line segment

Math 6 Chapter 1 Lesson 10: Midpoint of line segment 1. Theory The midpoint of line segment AB is the point M on that line and is equidistant from two points A and B. We have: M is the midpoint of line segment AB \( \Leftrightarrow \left\{ \begin{array}{l}M \in AB\\MA = MB\end{array} \right.\) Or M is midpoint of line segment AB \( \Leftrightarrow … [Read more...] about Math 6 Chapter 1 Lesson 10: Midpoint of line segment