Content
- Informal Statement 1
- The sum of the angles of a triangle is equal to a striaght angle
- Informal Statement 2
- Two straight lines can intersect at only one point
- Informal Statement 3
- A line can be divided into two equal parts by only one point
- Informal Statement 4
- An angle can be divided into two parts by only one line
- Informal Statement 5
- All straight lines are equal
- Informal Statement 6
- All right angles are equal
- Informal Statement 7
- Only one perpendicular line can be drawn to a line at a point in the line
- Informal Statement 8
- Compliments of equal angles or of the same angle are equal
- Informal Statement 9
- Supplements of equal angles or of the same angle are equal
- Informal Statement 10
- The sum of all angles about a point on one side of a straight line through the point is a straight angle
- Informal Statement 11
- The sum of all angles about a point is equal to 360 degrees
- Informal Statement 12
- If the sum of two adjacent angles is equal to a straight angle, their exterior sides form one straight line
- Informal Statement 13
- When two straight lines intersect, the vertical angles formed are equal
- Informal Statement 14
- The sum of two sides of a triangle is greater than the third side
- Informal Statement 15
- In any polygon, the sum of an exterior angle and the adjacent interior angle is equal to a right angle
- Informal Statemtent 16
- In any polygon with n vertices, the sum of (one group of exterior angles?) and all interior angles = n straight angles