If you're seeing this message, it means we're having trouble loading external resources for Khan Academy.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Skip to main content
Subjects
  • Math
    • Early math
    • 3rd grade (U.S.)
    • 4th grade (U.S.)
    • 5th grade (U.S.)
    • 6th grade (U.S.)
    • 7th grade (U.S.)
    • 8th grade (U.S.)
    • Arithmetic
    • Pre-algebra
    • Algebra basics
    • Algebra I
    • Basic geometry
    • Geometry
    • Algebra II
    • Trigonometry
    • Probability and statistics
    • Precalculus
    • Differential calculus
    • Integral calculus
    • Multivariable calculus
    • Differential equations
    • Linear algebra
    • Math for fun and glory
  • Science
    • Biology
    • Physics
    • Chemistry
    • Organic chemistry
    • Cosmology and astronomy
    • Health and medicine
    • Electrical engineering
  • Economics and finance
    • Microeconomics
    • Macroeconomics
    • Finance and capital markets
    • Entrepreneurship
  • Arts and humanities
    • Grammar
    • Music
    • US history
    • World history
    • Art history basics
    • Prehistoric art in Europe and West Asia
    • Art of the ancient Mediterranean
    • Art of Medieval Europe
    • Art of the Islamic world
    • Renaissance & Reformation in Europe
    • Baroque to Neoclassical art in Europe
    • Art of the Americas to World War I
    • Art in 19th century Europe
    • Expressionism to Pop Art
    • Global contemporary art
    • Art of Asia
    • Art of Africa
    • Art of Oceania
    • For teachers
  • Computing
    • Computer programming
    • Computer science
    • Hour of Code
  • Test prep
    • SAT
    • MCAT
    • NCLEX-RN
    • GMAT
    • CAHSEE
    • IIT JEE
    • AP* Art History
  • KA Educator
    •KhanAcademy
    DonateSign in / Sign up
    Search for subjects, skills, and videos
    
    Main content

    Basic geometry

    Explore

    Table of contents

    Topics

    Lines
    Angles
    Shapes
    The coordinate plane
    Area and perimeter
    Volume and surface area
    The Pythagorean theorem
    Transformations, congruence, and similarity
    See descriptions

    Staff picks

    3:38
    Lines, line segments, & rays
    Lines, line segments and rays
    Exercise
    Draw angles
    Angle basics
    Exercise
    Coordinate plane problems in all four quadrants
    Coordinate plane
    11:05
    Radius, diameter, circumference & π
    Area and circumference of circles
    Exercise
    Nets of polyhedra
    Surface area

    Get Started

    Lines, line segments and rays
    Let's draw points, lines, line segments, and rays. We'll also think about perpendicular and parallel lines and identify these in two-dimensional figures. Common Core Standard: 4.G.A.1
    Start Learning
    Table of contents