What is the equation (s) for the circumference of a circle?
C=2πr or C=πd
What is the equation for the area of a circle?
A = πr^2
What is the equation for the area of a semicircle?
A = (πr^2)/2
Describe the process needed to calculate the area of a composite figure. (Explain the 4 individual steps)
1. Identify and divide the composite figure into recognizable basic shapes (rectangles, triangles, circles, etc.).
2. Use the appropriate formula or equation for each simple shape
3. If the composite figure is made of multiple shapes, add their areas together. If a part of the shape is missing (such as a hole or cut-out), subtract the area of that part.
4. Ensure your final answer has the correct square units (e.g., cm², in², m²).
Find the circumference of a circle with a diamter of 16.6yds. Use 3.14 for pi and round to the tenth place
52.1 yd
Find the area of the circle with a radius of 12cm. Use 3.14 for pi
452.16 cm2
What is the equation for the perimeter of a semicircle?
P = (πd)/2 + d
Find the area of the composite shape.
189.25 in2
Find the circumference of a circle with a diameter of 8.4yds. Use 3.14 for pi and round to the tenth place
26.4 yd
Find the area of the circle with a radius of 6km. Use 3.14 for pi
approximately 113.0 km2
Find the area of the semicircle with a diameter of 8 in. Use 3.14 for pi
25.12 in2
Find the area of the composite shape.
21.5cm2
Find the circumference of a circle where the radius is 9.5 in Round to the tenth.
59.7 in
Find the area of a circle with a diameter of 26.4km. Round to the tenth.
approximately 547.1km2
Find the perimeter of the semicircle with a diameter of 8 in. Use 3.14 for pi
20.56 in
Find the area and perimeter of the composite shape.
Area = 53.12 ft²
Perimeter = 30.56 ft
Find the radius of the circle given the circumference of 62.8 mi
10 mi
Find the diameter of the circle given the area of 78.5 ft²
10 ft
If the area of a semicircle = 14.13 in2 what is the diameter?
6in
Find the area and perimeter of the composite shape.
Area = 78 cm²
Perimeter = 44 cm