How to find perimeter and area of semicircle if diameter is 4. and a semicircle with diameter 2. use it in term of pie.

To find the perimeter, known as circumference, of a circle, the formula is C=πd. Since this is a semicircle, just divide it by 2. 4 times 3.14 is 12.56, divided by 2 is 6.28. The formula for the area of a circle is A=πr^2. The radius of this circle is  2, obviously. 2 times 2 is four. four times 3.14 is 12.56, divided by 2 is 6.28 units squared.

Circumference= 6.28 units
Area= 6.28 units squared