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

3.5

Step-by-step explanation:

Whenever you do 2.25 x 4 you get 9, then you add 7.50 and get 16.5. Afterwards, you subtract 3.5 from 20 leaving you with $3.5 dollars.