Basic 2D Shapes Names
In geometry, a two-dimensional shape, also known as a plane figure, is a shape that has only two dimensions: length and width. It has no thickness or depth. Here are some basic 2D shapes names that you should know:
1. Circle
A circle is a closed curve made up of points that are all the same distance from a center point.
Key features:
- Radius: The distance from the center of the circle to any point on the circle.
- Diameter: The distance across the circle passing through the center.
- Circumference: The distance around the circle.
2. Square
A square is a four-sided polygon where all sides are equal in length and all angles are right angles (90 degrees).
Key features:
- Sides: All four sides are equal.
- Angles: All four angles are right angles (90 degrees).
- Area: Side length squared (s²)
- Perimeter: 4 times the side length (4s)
3. Rectangle
A rectangle is a four-sided polygon where opposite sides are equal in length and all angles are right angles.
Key features:
- Sides: Opposite sides are equal.
- Angles: All four angles are right angles (90 degrees).
- Area: Length x Width (l x w)
- Perimeter: 2 x (Length + Width) 2(l + w)
4. Triangle
A triangle is a three-sided polygon.
Key features:
- Sides: Can have different lengths.
- Angles: The sum of the interior angles of a triangle is always 180 degrees.
- Types of triangles: There are different types of triangles based on their angles and sides.
Types:
- Equilateral triangle: All three sides are equal, and all three angles are 60 degrees.
- Isosceles triangle: Two sides are equal, and two angles are equal.
- Scalene triangle: All three sides are different lengths, and all three angles are different.
- Right triangle: One angle is a right angle (90 degrees).
5. Polygon
A polygon is a closed figure made up of straight line segments.
Key features:
- Sides: Made up of straight line segments.
- Angles: The sum of the interior angles of a polygon is dependent on the number of sides.
Types:
- Regular polygon: All sides are equal, and all angles are equal.
- Irregular polygon: Sides and angles may have different sizes.
6. Pentagon
A pentagon is a five-sided polygon.
Key features:
- Sides: Has five sides.
- Angles: The sum of the interior angles of a pentagon is 540 degrees.
7. Hexagon
A hexagon is a six-sided polygon.
Key features:
- Sides: Has six sides.
- Angles: The sum of the interior angles of a hexagon is 720 degrees.
8. Octagon
An octagon is an eight-sided polygon.
Key features:
- Sides: Has eight sides.
- Angles: The sum of the interior angles of an octagon is 1080 degrees.
These are just a few of the many basic 2D shapes. Learning about their properties and how to identify them will help you understand the world around you better.
