The area is the size of a two-dimensional closed surface (the number of unit squares that cover the surface of the figure).
The area is measured in square units. We can use mm², cm², m², km², inches², yards², miles² or any other length square unit.
Area of a rectangle
We can find the area counting the number of square units. The area of the following rectangle is 6 square units.
The number of unit squares in each row is the length of the rectangle.
The number of rows is the height of the rectangle
Area of the rectangle = length × height = 3 × 2 = 6 square units
Area of a parallelogram
A parallelogram is a quadrilateral with two pairs of parallel sides.
The base length is L and the distance between parallels is the height H.
We can transform a parallelogram into a rectangle, removing the right-angled triangle on the right and adding it on the left, as shown.
Always remember that length and height must meet at a right angle.
Area of the parallelogram = length × height
A rectangle has two diagonals (line segments linking opposite vertices)
Area of the triangle
A rectangle has two diagonals (line segments linking opposite vertices).
Each diagonal divides the rectangle into two congruent right triangles (each with half the area of the rectangle).
If we cut a rectangle in half diagonally we have two congruent right triangles.
The area of each triangle is ½ length × height.
Also, if we cut a parallelogram in half diagonally we have two congruent triangles, as shown:
The area of each triangle is ½ length × height.
GE16 Area of a Triangle 1
GE17 Area of a Triangle 2
GE18 Area of a Triangle 3
AR01 Quiz Area
Perimeter&Area_(Help)