Quadrilaterals have been included in the Primary 2 Math curriculum so that students can gradually become familiar with the shapes and then perform math problems of calculating the perimeter of a triangle, the perimeter of a rectangle or calculating the area. trapezium…. Below is all the knowledge to calculate the perimeter of a quadrilateral and the area of a quadrilateral.
1. What is a quadrilateral?
A quadrilateral is a shape with 4 edges and 4 vertices. A quadrilateral can be a simple quadrilateral when no pair of opposite sides intersect or a double quadrilateral when two pairs of opposite sides intersect. The sum of quadrilateral angles is 360 degrees.
2. Formula to calculate the perimeter of a quadrilateral
To calculate the perimeter of a quadrilateral is very simple, you add all the sides in the quadrilateral.
General formula for calculating the perimeter of a quadrilateral:
P = a + b + c + d
In there:
- P is the perimeter of the quadrilateral
- a, b, c, d are the lengths of the sides of the quadrilateral, respectively
Example of calculating the perimeter of a quadrilateral
1. Calculate the perimeter of a quadrilateral with sides AB = 5cm, BC = 7cm, CD = 9cm and DA = 5cm.
According to the formula for calculating circumference, we will have the calculation: P = 5 + 7 + 9 + 5 = 26cm.
2. Quadrilateral ABCD has a perimeter of 73cm, knowing the total length of sides AB and BC is 52cm. Calculate the total length of sides CD and DA?
The perimeter of quadrilateral ABCD is P = AB + BC + CD + DA.
From there 73 = 52 + (CD + DA) = 73 – 52 = 21cm.
3. Formula to calculate the area of a quadrilateral
There is no general formula to calculate the area of a quadrilateral. We rely on the specific nature of the quadrilateral to have different ways to calculate the area.
