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Symbol Defintion
Example x^2 = square of x
GE 01 01. Various names of angles
Diagrams : Definition of various angles
- Subjects | Program 01 01 : Various names of angles
- Start the diagram program, find names of angles
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GE 01 02. Angles of triangle
Triangle ABC
- 1. Sum of three angle is 180 degrees or pi radians
- 2. Each internal angle has an external angle and they are supplementary angles
- 3. Supplemenary angle of C = angle A + angle B = External angle of angle C
- Supplementary angle of C = 180 - angle C
- Angle A + angle B = 180 - angle C
- Hence Supplemenary angle of C = angle A + angle B
- 4. Right triangle has one 90 degree angle
- 5. External angles
- External angle of angle A = angle B + angle C
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GE 01 03. Definition of an angle
Defintion
- An angle has two rays with one common point
- Degrees or radians
- One radian = 180/pi degrees
- One degree = pi/180 radians
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GE 01 04. Bisect an angle
Diagram
- Start the diagram program 02 02
- Find the steps to bisect an angle
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GE 01 05. Draw a line parallel to other line
- Give the name of angles
- Write down the conditions so that two lines are parallel
- 1. Draw line A
- 2. Draw line B cross line A
- 3. On the line pick a point P
- 4. At P draw line C which has equal a coresponding angle with line A
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GE 01 06. Angle related with circle
- Start the diagram program and click Menu
- Find the relation of central angle with chord-tangent angle
- 1. Draw the angle related with circle
- 2. Use protractor find the relation of inscribed angle and central angle
- 3. Use protractor find the relation of inscribed angle and tangent-chord angle
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GE 01 07. External angle of angle B = angle A + angle C
- Draw a triangle ABC and let AB be in horizontal direction
- Produce AB to D, then angle DBE is external angle of B
- AT B draw a line BE parallel to AC
- Since BE parallel to AC
- Hence angle EBC = angle C (Alternate angles)
- Hence angle DBE = angle A (Corresponding angle)
- Hence angle DBC = angle A + angle C
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GE 01 08. Answer
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GE 01 09. Answer
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GE 01 10. Exercises
Question 1
- Draw a large triangle ABC. Let angle C = 90, Angle A = 30
- Measure AB and BC
- Find AB : BC = ?
- Try few times and give a conclusion
- Draw a large triangle ABC. Let angle C = 90, Angle A = 30
- Measure AB, BC and CA
- Find AB sqaure, BC square and CA square
- Find BC square + CA square = ?
- Try few times and give a conclusion
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GE 01 00. Outlines
Angles
- 01 Acute angle is between 0 and 90 degrees
- 02 Right angle is equal to 90 degrees
- 03 obtuse angle is between 90 and 180 degrees
- 04 Straight angle is equal 180 degrees
- 05 Angle related with two parallel lines
- 06 Central angle of circle is equal the subtendded arc
- 07 Inscribed angle of circle is equal half of the subtendded arc
- 08 Tangent and chord angle is equal related inscribed angle
- Sum of internal angles is equal to pi
- External angle of angle B is equal to angle A plus angle C
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