Unlocking Quadrilaterals: Your Step-by-Step Guide 📐
Quadrilaterals are fundamental geometric shapes. Let's explore them!
What is a Quadrilateral? 🤔
A quadrilateral is a polygon with four sides, four vertices, and four angles. The sum of its interior angles is always 360 degrees. Let's explore the different types.
Types of Quadrilaterals 種類
- Square: 🟩 Four equal sides and four right angles (90°).
- Rectangle: 🏢 Four right angles, with opposite sides equal.
- Parallelogram: ▱ Opposite sides are parallel and equal. Opposite angles are equal.
- Rhombus: 🔶 Four equal sides. Opposite angles are equal. Diagonals bisect each other at right angles.
- Trapezoid (Trapezium): ⬆️ At least one pair of parallel sides.
- Kite: 🪁 Two pairs of adjacent sides are equal.
Properties of Quadrilaterals 🔑
Understanding the properties of each quadrilateral helps in solving geometric problems.
- Square:
- All sides are equal.
- All angles are 90°.
- Diagonals are equal and bisect each other at 90°.
- Rectangle:
- Opposite sides are equal.
- All angles are 90°.
- Diagonals are equal and bisect each other.
- Parallelogram:
- Opposite sides are parallel and equal.
- Opposite angles are equal.
- Diagonals bisect each other.
- Rhombus:
- All sides are equal.
- Opposite angles are equal.
- Diagonals bisect each other at 90°.
- Trapezoid (Trapezium):
- At least one pair of parallel sides.
- Kite:
- Two pairs of adjacent sides are equal.
- One pair of opposite angles are equal.
- Diagonals intersect at 90°.
Area and Perimeter Formulas 📏
Here are the formulas to calculate the area and perimeter of common quadrilaterals:
- Square:
- Area: $A = s^2$ (where s is the side length)
- Perimeter: $P = 4s$
- Rectangle:
- Area: $A = lw$ (where l is length and w is width)
- Perimeter: $P = 2(l + w)$
- Parallelogram:
- Area: $A = bh$ (where b is base and h is height)
- Perimeter: $P = 2(a + b)$ (where a and b are adjacent side lengths)
- Rhombus:
- Area: $A = (d_1 * d_2) / 2$ (where $d_1$ and $d_2$ are the diagonals)
- Perimeter: $P = 4s$ (where s is the side length)
- Trapezoid (Trapezium):
- Area: $A = (h / 2) * (b_1 + b_2)$ (where h is the height, and $b_1$ and $b_2$ are the lengths of the parallel sides)
- Perimeter: $P = a + b_1 + b_2 + c$ (where a and c are the lengths of the non-parallel sides)
- Kite:
- Area: $A = (d_1 * d_2) / 2$ (where $d_1$ and $d_2$ are the diagonals)
- Perimeter: $P = 2a + 2b$ (where a and b are the lengths of the two distinct sides)
Example Code 💻
Here's a Python example to calculate the area of a rectangle:
def rectangle_area(length, width):
"""Calculates the area of a rectangle."""
area = length * width
return area
length = 5
width = 10
area = rectangle_area(length, width)
print(f"The area of the rectangle is: {area}")