On this website you will be learning the basics of geometry such as angles , finding measures of triangles , and trigonometry.
angles that lie on either side of a common arm are said to be adjacent.
A small square drawn between two lines indicates a right angle (that is, the two lines are perpendicular. That is, they cross at a 90° angle, exactly one-fourth of a full circle. A 90° angle is also called a right angle.