Answer:
Area:
4 x 4 = 16
Finding area of semi circle:
4 is your diameter so half of it is your radius which is 2 since half of 4 is 2!
2^2<---your radius being squared = 4
4(radius squared) x 3.14(pi) = 12.56
12.56 divided by 2 since its a semi circle is = 6.28
6.28 + 16 = 22.28 is your area
Perimeter is:
4 + 4 + 4 (all sides of a square are equal therefore one or two given lengths will be all the sides) = 12
Circumference:
Radius is 2,
2(you just always have to multiply this number when finding circumference) x 3.14(pi) x 2(radius), 2 x 3.14 x 2 = 12.56
12.56 divided by 2 = 6.28
6.28 + 12 = 18.28 is your perimeter.
Just a refresh:
Circumference Formula:
2(always use this number when finding circumference) x pi(3.14 or 22/7 depending on what they tell you to use for pi) x radius
Area of a Circle Formula:
Radius squared x pi(3.14 or 22/7 whatever they tell you to use for pi)
Another thing you should remember:
Whenever it gives you 1/4 of a circle or 1/3 or a semi circle or any fraction, REMEMBER TO DIVIDE BY THAT DENOMINATOR TO WHAT YOU GET FROM EITHER CIRCUMFERENCE OR AREA OF A CIRCLE!