Question

assignment – 2-dimensional geometry, day 4
area of circles day 1
grade 7
recent

1. find the radius if the circumference is about 113.04 meters. use π = 3.14.

today
find the area.

1. use π = 3.14 to find the area of a circle with a diameter of 10 meters.
2. use π = 3.14.

1. leave in terms of π.

1. use π = \\(\frac{22}{7}\\).

all year

1. tucker is buying new shirts for his bowling team. each shirt costs $24 and the company charges $15.99 for delivery. write an equation that can be used to find tucker’s total cost, y, if he buys x shirts. enter your answer in the box.

Explanation:

Step1: Solve for radius (Q1)

Circumference formula: $C = 2\pi r$. Rearrange to $r = \frac{C}{2\pi}$. Substitute $C=113.04$, $\pi=3.14$: $r = \frac{113.04}{2×3.14} = 18$ meters.

Step2: Calculate area (Q2)

Radius = diameter/2 = $10/2 = 5$ m. Area formula: $A = \pi r^2$. Substitute $\pi=3.14$, $r=5$: $A = 3.14×5^2 = 78.5$ m².

Step3: Calculate area (Q3)

Radius = 16 in. Area: $A = 3.14×16^2 = 3.14×256 = 803.84$ in².

Step4: Calculate area (Q4)

Diameter = 9.2 mm → radius = $9.2/2 = 4.6$ mm. Area in terms of $\pi$: $A = \pi×4.6^2 = 21.16\pi$ mm².

Step5: Calculate area (Q5)

Radius = 21 cm. Area: $A = \frac{22}{7}×21^2 = \frac{22}{7}×441 = 1386$ cm².

Step6: Form total cost equation (Q6)

Total cost = (cost per shirt × number of shirts) + delivery fee: $y = 24x + 15.99$.

Answer:

1. 18 meters
2. 78.5 square meters
3. 803.84 square inches
4. $21.16\pi$ square millimeters
5. 1386 square centimeters
6. $y = 24x + 15.99$