The formula for calculating the area of ​​a trapezoid, the circumference of a trapezoid is complete, easy to understand

In today's life, we have to encounter the formulas to calculate the perimeter and area of ​​a trapezoid twice twice. This article will give you the concept, the formula for calculating perimeter and area of ​​each type.

1. Normal trapezoidal shape

Concept : A trapezoid is a convex quadrilateral with two parallel base sides, the other two sides are called two sides.

- The formula for calculating the area of ​​a trapezoid usually

The area of ​​a trapezoid is equal to the average of the two bases multiplied by its height.

S = hx ((a + b) / 2)

In which :

+ S: Area.

+ a, b: The lengths of the bottom 2 respectively.

+ h: Height of a trapezoid.

I will guide you to calculate the area of ​​a trapezoid above through the following example:

A trapezoid with height = 4cm, baby bottom a = 5cm, big bottom b = 12cm. The area of ​​the trapezoid above?

Apply the formula S = hx ((a + b) / 2) = 4 x ((5 + 12) / 2) = 34 (cm).

- The formula for calculating the perimeter of the trapezoid

The circumference of a trapezoid is equal to the sum of its sides and base.

P = a + b + c + d.

Inside:

+ P: Perimeter of a trapezoid.

+ a, b: The lengths of the bottom two sides respectively.

+ c, d: Turn to be a team with 2 sides.

A trapezoid has the side lengths of 8cm, the bottom length of the baby, the big bottom being 8cm and 16cm respectively. Calculate the circumference of the trapezoid mentioned above?

We have the formula: P = a + b + c + d = 8 + 8 + 8 +16 = 40cm.

- Formula to calculate the area of ​​a trapezoid when knowing the length of 4 sides

We have the following formula:

In which :

+ a, b: the lengths of the bottom two sides respectively.

+ c, d: the team with 2 side length respectively.

2. Square trapezoid

Concept : A square trapezoid is a special kind of trapezoid. A square trapezoid has two right angles, its height and side sides perpendicular to the bottom two sides.

The formula for calculating the area of ​​a square trapezoid

S = hx ((a + b) / 2)

In which :

+ S: Area.

+ a, b: The lengths of the bottom 2 respectively.

+ h: Height of a trapezoid.

An ABHD square trapezoid has a bottom length of 8cm and 12cm, respectively. In which side AH = 8cm. Calculate the area of ​​that square trapezoid.

Apply the formula: S = hx ((a + b) / 2) = 8 x ((8 + 12) / 2) = 80cm.

3. Isosceles trapezoidal shape

Concept : An isosceles trapezoid is a shape with two equal sides, two equal angles created by the side and the bottom.

The formula for calculating the area of ​​an isosceles trapezoid

To calculate the area of ​​an isosceles trapezoid, we can either calculate the general formula above or divide the isosceles trapezoid into 1 square and 2 right triangles, calculate the area of ​​each shape and add them.

S = hx ((a + b) / 2).

In which :

+ S: area.

+ a, b: lengths of 2 bottoms respectively.

+ h: height of a trapezoid.

Example: S = hx ((a + b) / 2) = 8 x ((8 + 16) / 2) = 96cm.

S = 2 x S.ACH + S.ABHF = 2 x 1/2 x 8 x 4 + 8 x 8 = 96cm.

4. Notes when calculating the area and perimeter of the trapezoid

Note the unit length of the sides of a trapezoid.

In the process of solving the problem, sometimes you will wonder if a trapezoid has a volume? Then the answer is no. Since a trapezoid is essentially a two-dimensional geometry, the volume of the trapezoid cannot be calculated.

See also :

>>> Equations to calculate the area of ​​a circle, the most complete circle's perimeter

>>> Synthesize a table of full, detailed and easy-to-understand trigonometric formulas

So we have gone through each definition as well as the formula to calculate the area and perimeter of the trapezoid. Hope this article will be useful to you!