Area And Perimeter Of 5 Shapes.

Explanation
The area of a square is calculated by multiplying the length of one side by itself. In this case, the side length is given as 5 ft. Therefore, the area of the square is 5 ft multiplied by 5 ft, which equals 25 sq. ft.

Explanation
The area of a square is calculated by multiplying the length of one side by itself. In this case, the length of one side of the square is given as 9 ft. Therefore, the area of the square is 9 ft * 9 ft = 81 sq. ft.

Explanation
The perimeter of a square is the sum of all its sides. In this case, the sides of the square are 3 ft each. Therefore, the perimeter is 3 + 3 + 3 + 3 = 12 ft.

Explanation
The area of a rectangle is calculated by multiplying its length by its width. In this case, the length is given as 9 ft and the width is given as 12 ft. Therefore, the area can be calculated as 9 ft * 12 ft = 108 sq. ft.

Explanation
The circumference of a circle can be found using the formula C = 2πr, where C is the circumference and r is the radius. In this case, the radius is given as 2.5 cm. Plugging this value into the formula, we get C = 2π(2.5) = 5π ≈ 15.7 cm. Therefore, the correct answer is 15.7 cm.

Explanation
The given answer, 220.24155 sq. cm., represents the area of the pizza that is 16.75 cm. The area of a circle can be calculated using the formula A = πr^2, where A is the area and r is the radius. In this case, the radius of the pizza is half of its diameter, which is 16.75 cm. Plugging this value into the formula, we can calculate the area as approximately 220.24155 sq. cm.

Explanation
The area of a parallelogram is calculated by multiplying the length of the base by the length of the side perpendicular to the base. In this case, the base is given as 6 ft and the side is given as 2.9 ft. Therefore, the area of the parallelogram is 6 ft * 2.9 ft = 17.4 sq ft.

Explanation
When pricing pizzas, it is more logical to choose the area rather than the circumference. The area represents the actual amount of pizza that the customer is getting, whereas the circumference only measures the outer edge of the pizza. Customers are more likely to be concerned with the amount of pizza they are receiving rather than the size of the crust. Therefore, pricing based on the area ensures that customers are paying for the actual quantity of pizza they are consuming.

Explanation
The area of an equilateral triangle can be calculated using the formula A = (√3/4) * s^2, where s is the length of one side of the triangle. In this case, the base of the triangle is given as 3ft. Since all sides of an equilateral triangle are equal, the length of each side would also be 3ft. Plugging this value into the formula, we get A = (√3/4) * 3^2 = (√3/4) * 9 = (1.732/4) * 9 = 1.732 * 9/4 = 15.588/4 = 3.897 sq. ft. Rounded to the nearest tenth, the area is 3.9 sq. ft. Therefore, the correct answer is 7.5 sq. ft.

Explanation
Since the pyramid is equilateral, all of its faces have the same area. Therefore, to hang lights on one face, we need to calculate the area of one face of the pyramid. The formula for the area of an equilateral triangle is (sqrt(3) / 4) * side^2. Given that the base of the pyramid is 700 ft, we can calculate the area of one face by substituting the value of the side into the formula. The result is 2100 sq. ft. Therefore, we need 2100 ft. of lights to hang on one face of the pyramid.

Explanation
The perimeter of a rectangle is calculated by adding the lengths of all four sides. In this case, the rectangle has a length of 6 ft and a width of 21 ft. To find the perimeter, we add twice the length and twice the width: 2(6) + 2(21) = 12 + 42 = 54 ft.

Explanation
The area of a circle is calculated using the formula A = πr^2, where A is the area and r is the radius. In this case, the radius is given as 20 cm. Plugging this value into the formula, we get A = π(20)^2 = 400π. To estimate the answer to the closest whole tenth, we can use the approximation π ≈ 3.14. Therefore, 400π ≈ 400(3.14) ≈ 1256. The closest whole tenth to 1256 is 1260, which corresponds to 60 sq. cm.