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Last updated on September 17, 2025
Area is the space inside the boundaries of a two-dimensional shape or surface. Different formulas are used to find the area of various shapes/figures. These formulas are widely used in architecture and design. In this section, we will find the area of an oval.
An oval is an elongated circle, commonly referred to as an ellipse.
It has two main axes: the major axis and the minor axis. The area of an oval is the total space it encloses.
To find the area of an oval, we use the formula: π × a × b, where 'a' is the semi-major axis and 'b' is the semi-minor axis. Now let’s see how the formula is derived.
Derivation of the formula:- An oval is symmetrical about both its axes. The semi-major axis 'a' is half the length of the longest diameter, while the semi-minor axis 'b' is half the length of the shortest diameter.
The area of an ellipse is derived from its geometric properties, giving us the formula: Area = π × a × b Therefore, the area of the oval = π × a × b
We can find the area of an oval using the formula involving the semi-major and semi-minor axes. Here's how to use the formula:
Method Using the Semi-Major and Semi-Minor Axes
If the semi-major axis 'a' and semi-minor axis 'b' are given, we find the area of the oval using the formula: Area = π × a × b
For example, if 'a' and 'b' are 5 cm and 3 cm, the area of the oval will be: Area = π × a × b = π × 5 × 3 = 15π The area of the oval is approximately 47.12 cm² (using π ≈ 3.14).
We measure the area of an oval in square units. The measurement depends on the system used:
In the metric system, the area is measured in square meters (m²), square centimeters (cm²), and square millimeters (mm²).
In the imperial system, the area is measured in square inches (in²), square feet (ft²), and square yards (yd²).
Ovals can vary, but the most common is the ellipse. Here are some special cases:
Case 1: Use of Semi-Major and Semi-Minor Axes If 'a' and 'b' are given, use the formula: Area = π × a × b
Case 2: Using Trigonometry for Elliptical Segments If only segments of the ellipse are considered, trigonometric functions may be used to calculate the area of those segments.
To ensure accurate results while calculating the area of an oval, consider these tips and tricks:
1. Ensure you correctly identify the semi-major and semi-minor axes.
2. Use the value of π accurately (3.14 or more decimal places for more precision).
3. Always check the units of measurement and convert if necessary to maintain consistency.
It is common for people to make mistakes while finding the area of an oval. Let’s take a look at some mistakes made:
The semi-major axis 'a' and semi-minor axis 'b' of an oval-shaped garden are given as 7 m and 4 m. What will be the area?
We will find the area as 28π m²
Here, the semi-major axis 'a' is 7 m and the semi-minor axis 'b' is 4 m.
The area of the oval = π × a × b = π × 7 × 4 = 28π m².
The approximate area is 87.92 m² (using π ≈ 3.14).
What will be the area of the oval if the semi-major and semi-minor axes are given as 10 cm and 6 cm?
We will find the area as 60π cm²
If the semi-major axis 'a' and semi-minor axis 'b' are given, we use the formula: area = π × a × b.
Here, 'a' and 'b' are 10 cm and 6 cm.
Hence, the area will be π × 10 × 6 = 60π cm².
The approximate area is 188.4 cm² (using π ≈ 3.14).
The area of an oval is 150π m², and the length of the semi-major axis 'a' is 10 m.
We find the length of the semi-minor axis 'b' as 15 m.
To find the semi-minor axis 'b', we use the formula: area = π × a × b.
Here, the area is 150π m², and 'a' is 10 m.
By substituting the values given, we find 'b': 150π = π × 10 × b 150 = 10 × b b = 150/10 = 15 m
Seyed Ali Fathima S a math expert with nearly 5 years of experience as a math teacher. From an engineer to a math teacher, shows her passion for math and teaching. She is a calculator queen, who loves tables and she turns tables to puzzles and songs.
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