 ### Angle

Finding the angle between two lines whose equations are in intercept form. ### Triangle Area

Finding the area of a triangle in terms of polar coordinates of its three vertices. ### Oblique Axes

Angles on a modified coordinate plane. ### Rectangular Axes

Transforming from one set of rectangular axes to another with the same origin, but different direction. ### Circle

A circle and triangle situated on coordinate planes. ### Common Form of Circle

A circle in its common, or central form. This is used to assist students in finding the equation of… ### Rectangular Coordinates

Changing from polar to rectangular coordinates. ### Perpendicular Distance

Finding the perpendicular distance of points whose equation is x cosa + y sina = p. ### Chord Equation

Tangent lines are drawn from a given external point to a circle. The equation is found by joining their… ### Circle Equation

Finding the equation of a circle with the origin as its center. ### Line Equation

Finding the equation of a line through two given points. ### Normal Equation

Finding the equation of the normal at any point on a circle. ### General Form

A line with a standard form equation. ### Intercept Form

A line with intercept form equation. ### Given Incline

Equation of a line with two given points and a given inclination. ### Straight Line

Equation of a straight line: a) parallel to y-axis, b) parallel to x-axis. ### Straight Line

A positive slope line making a 60 degree angle with the x-axis. ### Lines

A circle with many tangent and secant lines passing through it. ### Alternate Method

Another method for using perpendicular form. ### The Origin

A straight line through the origin of a coordinate plane. ### Alternate Form, Perpendicular Distance

An alternate form of the perpendicular distance method. ### Coordinate Plane

A circle with part of a triangle inscribed in it. They are lying on a coordinate plane. ### Given Point

Finding the equation of a line drawn through a given point at a given direction. ### Axes Shift

Any system of coordinate axes to another set which is parallel to the former, but with different origins.