Properties of triangles and angles
Types of Angles
1) An acute angle is an angle which is more than 0 degrees and at the same time lesser than 90 degrees.
2) A right angle is a 90 degrees angle.
3) An obtuse angle is an angle which is more than 90 degrees and at the same time lesser than 180 degrees.
4) A straight line is 180 degrees.
5) A reflex angle is an angle which is more than 180 degrees and at the same time lesser than 360 degrees.
6) A complete turn is 360 degrees.
Types of Triangles
1) An equilateral triangle is a triangle with three sides of equal length, also known as the regular triangle. It is a special case of an isosceles triangle with three equal sides.
2) An isosceles triangle is a triangle with two sides of equal length. Angles opposite to equal side lengths are equal.
3) A scalene triangle is a triangle with all three side of unequal length.
4) An acute triangle is a triangle in which all three angles are less than 90 degrees.
5) A right triangle is a triangle with a 90 degrees angle.
6) An obtuse triangle is a triangle with one of the angles more than 90 degrees.
Basic Properties of Angles
1) When two straight line cross, vertically opposite angles are equal.
2) If parallel lines are cut by another line :
- Corresponding angles are equal.
- Alternate angles are equal. (Look for a Z shape)
- Interior angles between parallel lines adds up to 180 degrees.
3) The sum of the 3 angles of a triangle will always be 180 degrees.
4) The exterior angle sum of any polygon will always be 360 degrees.
1) An acute angle is an angle which is more than 0 degrees and at the same time lesser than 90 degrees.
2) A right angle is a 90 degrees angle.
3) An obtuse angle is an angle which is more than 90 degrees and at the same time lesser than 180 degrees.
4) A straight line is 180 degrees.
5) A reflex angle is an angle which is more than 180 degrees and at the same time lesser than 360 degrees.
6) A complete turn is 360 degrees.
Types of Triangles
1) An equilateral triangle is a triangle with three sides of equal length, also known as the regular triangle. It is a special case of an isosceles triangle with three equal sides.
2) An isosceles triangle is a triangle with two sides of equal length. Angles opposite to equal side lengths are equal.
3) A scalene triangle is a triangle with all three side of unequal length.
4) An acute triangle is a triangle in which all three angles are less than 90 degrees.
5) A right triangle is a triangle with a 90 degrees angle.
6) An obtuse triangle is a triangle with one of the angles more than 90 degrees.
Basic Properties of Angles
1) When two straight line cross, vertically opposite angles are equal.
2) If parallel lines are cut by another line :
- Corresponding angles are equal.
- Alternate angles are equal. (Look for a Z shape)
- Interior angles between parallel lines adds up to 180 degrees.
3) The sum of the 3 angles of a triangle will always be 180 degrees.
4) The exterior angle sum of any polygon will always be 360 degrees.
