If a ray stands on a line then the sum of two adjacent angles so formed is 180°.
If two lines intersect each other, then the vertically opposite angles are equal.
Acute angle measures between 0° and 90°.
If a transversal intersects two parallel lines, then each pair of corresponding angles is equal
If a transversal intersects two lines such that a pair of corresponding angles is equal, then the lines are parallel to each other.
If a transversal intersects two parallel lines, then each pair of alternate interior angles is equal.
If a transversal intersects two lines such that a pair of alternate interior angles is equal, then the two lines are parallel.➢ Two angles whose sum is 90° are called complementary angles.
Interior angles on the same side of transversal are called co-interior angles.The sum of angles of a triangle is 180°.
If a transversal intersects two parallel lines, then each pair of interior angles on the same side of transversal is supplementary.
If a transversal intersects two lines such that a pair of interior angles on the same side of transversal is supplementary, then the two lines are parallel.
If a side of a triangle is produced, then the exterior angle so formed is equal to sum of two interior opposite angles
Lines which are parallel to the same line are parallel to each other.
Right angle is exactly equal to 90°.
Obtuse angle measures between 90° and 180°.
Straight angle is exactly equal to 180°.
Reflex angle measures between 180° and 360°.
Complete angle is exactly equal to 360°.
Two angles whose sum is 180° are called supplementary angles.
Part of a line with two end paints is called a line segment.
Part of a line with one end point is called a ray
Three or more points lying on a line are called collinear points.
An angle is formed when two rays are drawn in different directions from a common initial point.
