Area and Perimeter of 2D: Circle, Triangle Area: Imagine a flat surface like a sheet of paper folded into a circle. This area represents the space insi...
Area:
Imagine a flat surface like a sheet of paper folded into a circle. This area represents the space inside the circle, regardless of its shape.
Area is directly related to the length of its perimeter and the radius of its circle.
The area of a circle is pi times the radius squared (πr²).
For example, the area of a circle with a radius of 5 cm is π × 5² cm² = 78.5 cm².
Perimeter:
Imagine a circular garden path with a length of 10 m. This is the perimeter of the circular path.
The perimeter of a circle is always the same regardless of its size. It is equal to 2πr, where r is the radius of the circle.
For instance, the perimeter of a circle with a radius of 3 cm is 2π × 3 cm = 18 cm.
Key Differences:
Area: The area tells us the amount of space enclosed by the circle, regardless of its shape.
Perimeter: The perimeter tells us the length of the boundary of the circle.
Examples:
A circle with radius 4 cm has an area of π × 4² cm² = 50.24 cm².
The perimeter of a circle with radius 3 cm is 2π × 3 cm = 18 cm.
Challenge:
Find the area of a circle with a diameter of 8 cm.
Calculate the perimeter of a triangle with sides of length 5 cm, 6 cm, and 7 cm