Choose a quadrilateral. Click the card to open solved examples and auto-checked practice.
Quadrilateral
Square
A square has 4 equal sides and 4 right angles.
Area = a²
Quadrilateral
Rectangle
A rectangle has opposite sides equal and 4 right angles.
Area = l × w
Quadrilateral
Parallelogram
A parallelogram has two pairs of parallel sides.
Area = base × height
Quadrilateral
Trapezium
A trapezium has one pair of parallel sides.
Area = ½(a+b)h
Square
A square has equal sides. To find area, multiply side × side.
Solved Examples
Example 1: side = 5 cm
- Formula: Area = a².
- Substitute: Area = 5².
- Calculate: Area = 25 cm².
Example 2: side = 8 cm
- Area = a².
- Area = 8².
- Area = 64 cm².
Example 3: side = 12 cm
- Area = a².
- Area = 12².
- Area = 144 cm².
Auto-Checked Practice
Rectangle
A rectangle has length and width. Multiply them to find area.
Solved Examples
Example 1: length = 10 cm, width = 6 cm
- Formula: Area = length × width.
- Substitute: Area = 10 × 6.
- Calculate: Area = 60 cm².
Example 2: length = 12 cm, width = 7 cm
- Area = length × width.
- Area = 12 × 7.
- Area = 84 cm².
Example 3: length = 15 cm, width = 9 cm
- Area = length × width.
- Area = 15 × 9.
- Area = 135 cm².
Auto-Checked Practice
Parallelogram
Use the straight height, not the slanted side. Area = base × height.
Solved Examples
Example 1: base = 12 cm, height = 5 cm
- Formula: Area = base × height.
- Substitute: Area = 12 × 5.
- Calculate: Area = 60 cm².
Example 2: base = 14 cm, height = 6 cm
- Area = base × height.
- Area = 14 × 6.
- Area = 84 cm².
Example 3: base = 18 cm, height = 8 cm
- Area = base × height.
- Area = 18 × 8.
- Area = 144 cm².
Auto-Checked Practice
Trapezium
Add the two parallel sides first. Then multiply by height and divide by 2.
Solved Examples
Example 1: a = 8 cm, b = 14 cm, h = 5 cm
- Formula: Area = ½(a + b)h.
- Substitute: Area = ½(8 + 14) × 5.
- Calculate: Area = 55 cm².
Example 2: a = 10 cm, b = 16 cm, h = 6 cm
- Area = ½(a + b)h.
- Area = ½(10 + 16) × 6.
- Area = 78 cm².
Example 3: a = 12 cm, b = 20 cm, h = 8 cm
- Area = ½(a + b)h.
- Area = ½(12 + 20) × 8.
- Area = 128 cm².