Properties of 2D Shapes
Properties of 2D Shapes
Rectangles and Squares
- A rectangle has four sides and four right angles.
- Opposite sides of a rectangle are of equal length.
- The area of a rectangle is calculated by multiplying the length and width (Area = Length x Width).
- A square is a special type of rectangle where all four sides are of the same length.
- The area of a square is calculated by squaring the length of one side (Area = Side x Side).
Triangles
- A triangle has three sides, and the sum of internal angles is always 180 degrees.
- There are three types of triangles: equilateral (all sides and angles are equal), isosceles (two sides and two angles are equal), and scalene (all sides and angles are different).
- The area of a triangle is derived by multiplying the base by the height and dividing by 2 (Area = 0.5 x Base x Height).
Circles
- A circle is a shape with all points the same distance from its centre.
- The distance around a circle is called the circumference.
- The distance across a circle through the centre is called the diameter.
- Half the diameter of a circle is called the radius.
- The area of a circle is given by pi times square of the radius (Area = π x Radius x Radius).
- The circumference of a circle can be calculated using π x Diameter or 2π x Radius.
Polygons
- Polygons are multi-sided figures.
- Common polygons include pentagon (5 sides), hexagon (6 sides), heptagon (7 sides), octagon (8 sides), and decagon (10 sides).
- The sum of internal angles in a polygon can be calculated as (Number of sides – 2) x 180.
- Regular polygons have all sides and angles equal, whereas irregular polygons do not.