Circumference= 2πr
circumference= 2×22/7×28
=8 ×22
circumference=176cm

Circumference of a Circle:

To find the circumference of a circle, we can use the formula:

C = 2πr

Where:
- C represents the circumference
- π (Pi) is a mathematical constant approximately equal to 3.14159
- r is the radius of the circle

Calculating the Circumference:

Given that the radius of the circle is 28 cm, we can substitute this value into the formula to find the circumference:

C = 2π(28)

To calculate this, we need to multiply 2 by π and then multiply the result by 28. Since π is a constant, we can use an approximation of 3.14159 for our calculations:

C ≈ 2(3.14159)(28)

Solution:

Now, let's solve the equation:

C ≈ 2(3.14159)(28)
C ≈ 6.28318 * 28
C ≈ 175.92984

Thus, the circumference of a circle with a radius of 28 cm is approximately 175.93 cm.

Summary:

To calculate the circumference of a circle, we can use the formula C = 2πr, where C represents the circumference, π is a constant (approximately 3.14159), and r is the radius of the circle. By substituting the radius value into the formula, we can calculate the circumference. In this case, the circumference of a circle with a radius of 28 cm is approximately 175.93 cm.