Find the arc length of the sector with a radius 9 units for a semi-circle.3 marks

Sure, here are the steps to find the arc length of the sector with a radius of 9 units for a semi-circle:

Step 1: Understand the problem We are given a semi-circle (which is half of a full circle) with a radius of 9 units. We need to find the arc length of this semi-circle.

Step 2: Recall the formula for the circumference of a circle The formula for the circumference of a full circle is 2πr, where r is the radius of the circle.

Step 3: Apply the formula Since we have a semi-circle (half of a full circle), we need to take half of the circumference. So, the arc length of the semi-circle is 1/2 * 2πr = πr.

Step 4: Substitute the given radius into the formula Substitute r = 9 units into the formula to get the arc length = π * 9 = 9π units.

So, the arc length of the sector with a radius of 9 units for a semi-circle is 9π units.