Test: Perimeter and Area - Class 4 MCQ

The perimeter is calculated as (5 + 5 + 5 + 5 = 20) cm. This example illustrates how to find the perimeter of regular shapes, such as squares or rhombuses, efficiently.

A ruler or measuring tape is ideal for measuring the perimeter of shapes, as it allows for precise measurement of each side's length, crucial for accurate calculations in real-world applications.

To approximate the area of irregular shapes, you count whole squares as 1 square unit, half squares as 0.5 square units, and squares covered more than half as whole units, while ignoring less than half. This method provides a practical approach to estimating area.

The area of a rectangle is calculated using the formula \( \text{length} \times \text{width} \). Therefore, \(5 \, \text{cm} \times 3 \, \text{cm} = 15 \, \text{sq. cm}\). This formula is fundamental in geometry for calculating the space within various shapes.

To find the area using a square grid, you trace the outline of the shape and count the number of unit squares it covers. This method provides a visual and straightforward way to understand area.

The area of a square is calculated using the formula 3 x 3 = 9 sq. cm. This formula is fundamental in geometry for calculating areas of squares.

Area is measured in square units, such as square centimeters (sq. cm) or square meters (sq. m). These units help convey the concept of two-dimensional space covered by a shape.

The perimeter of a square is calculated by adding the lengths of all four sides, which is (4 x 4 = 16) cm. Understanding square shapes can simplify calculations in geometry.

The area of the eraser is determined by the number of squares it covers. Since it covers 10 complete squares, the area equals 10 sq. cm. This straightforward counting method is useful for everyday measurements.

To find the width of the garden, we can use the formula for the perimeter of a rectangle:

• The formula for the perimeter (P) is: P = 2 × (length + width).
• We know the perimeter is 30 meters and the length is 8 meters.
• So, we can set up the equation: 30 = 2 × (8 + width).
• Next, divide both sides by 2: 15 = 8 + width.
• Now, subtract 8 from both sides: width = 15 - 8.
• This gives us: width = 7 meters.

The width of the garden is 7 meters.

Perimeter P = 50
Length L = 15

Formula:

P = 2 × (L + W)

Substitute values:

50 = 2 × (15 + W)

Divide both sides by 2:

25 = 15 + W

Subtract 15 from both sides:

W = 25 − 15

Width W = 10

Measuring the perimeter does not help in finding the area of a shape. Instead, area is found through methods like counting unit squares, tracing outlines, and estimating with half squares. Understanding these methods is crucial for accurately determining the space within shapes.

Since each square on the grid represents 1 sq. cm, an area covering 12 complete squares equals 12 sq. cm. This counting method simplifies area calculations in practical situations.

The perimeter is defined as the total distance around the boundary of a closed shape. To find it, you sum up the lengths of all the sides. This concept is essential for tasks like fencing or determining the outline of a space.

The key difference lies in their definitions: perimeter measures the distance around a shape, while area measures the space contained within that shape. This distinction is fundamental in geometry.