Coordinate Geometry

Distance formula, midpoint formula, and equations of lines

Start with the basics and progress through 3 lessons. Each lesson builds on the previous one.

In This Topic (3 lessons)

Coordinate geometry combines algebra and geometry, allowing geometric problems to be solved using equations. By placing shapes on a coordinate plane, we can calculate distances, slopes, midpoints, and determine relationships between lines and shapes using algebraic formulas. This powerful approach opens doors to advanced mathematics and real-world applications.

What You'll Learn

  • Calculate distance between points using the distance formula
  • Find midpoints of line segments
  • Determine slopes of lines
  • Write equations of lines given points or slopes
  • Apply coordinate geometry to geometric proofs

Frequently Asked Questions

What is the distance formula?

$d = \sqrt{(x_2-x_1)^2 + (y_2-y_1)^2}$, derived from the Pythagorean theorem applied to the horizontal and vertical distances between two points.

How do I find the equation of a line?

Use point-slope form $y - y_1 = m(x - x_1)$ with a point and slope, or slope-intercept form $y = mx + b$ with slope and y-intercept.

What makes lines parallel or perpendicular?

Parallel lines have equal slopes. Perpendicular lines have slopes that are negative reciprocals (their product equals -1).