Basic Shapes at a Glance

This is where it all begins: basic shapes, lines, and angles.

Read on and let us take you on a magical geometry tour...

NameDescriptionExample
Point
  • A single location.
  • Usually drawn as a dot.
  • It is "dimensionless".
  • Labeled as Point P. You used these when playing Connect the Dots.
Point P
Line
  • A straight path passing through at least two points.
  • Extends in both directions forever.
  • Labeled as QR
  • Think of this as a highway that never ends.
Line QR
Line Segment
  • A portion of a line.
  • It has limits at each end.
  • Labeled as CD
  • When writing the length of CD leave off the line like this: CD = length
  • You've drawn these since you were 1½!
Line segment CD
Ray
  • A straight path with one terminal point and extending indefinitely in the other direction.
  • Labeled as EF(Make sure to start with the terminal point and extend past the other point.)
  • Picture the sun as a terminal point and its rays extending indefinitely into space.
Ray EF
Plane
  • A flat surface without boundaries.
  • Labeled by naming three nonlinear points on the plane, Plane GHI.
  • It's like a piece of paper that extends in every direction forever.
Plane GHI
Parallel Lines
  • Lines that lie on the same plane and never intersect.
  • Labeled as JK and LM
  • Look at a piece of lined paper. All the horizontal lines are parallel to each other.
Parallel Lines JK and LM
Perpendicular Lines
  • Lines that intersect at a 90° angle.
  • Labeled as NQ and PO
  • On that same lined paper, the vertical margin lines are perpendicular to the horizontal lines you write on.
Perpendicular Lines NQ and PO

Example 1

Name each given shape.

a)

b)

c)

d)


Example 2

Name the following geometric shapes found in the image below:

  • a line
  • a pair of parallel lines
  • a pair of perpendicular lines
  • a ray
  • a line segment
  • the plane in which the lines lay


Example 3

How many points are needed to define a line and how many points are needed to define a plane?


Example 4

How many dimensions do the following basic shapes have?

  • a point
  • a line
  • a plane

Exercise 1

What is the intersection of two unique, non-parallel lines?


Exercise 2

What is the intersection of two unique, non-parallel planes?


Exercise 3

How many dimensions does a plane have?