Question

1. complete the table to determine the missing measurements for each object.

object	radius	diameter	circumference
circular pond			556 feet
magnifying glass		5.2 centimeters
car tire			71.6 inches

Explanation:

Step1: Recall circle formulas

For a circle, \( d = 2r \) (diameter = 2×radius) and \( C=\pi d = 2\pi r \) (circumference = \(\pi\)×diameter = 2×\(\pi\)×radius), use \(\pi\approx3.14\).

Step2: Hula hoop (d = 36 in)

• Radius: \( r=\frac{d}{2}=\frac{36}{2}=18 \) inches.
• Circumference: \( C = \pi d\approx3.14\times36 = 113.04 \) inches.

Step3: Circular pond (C = 556 ft)

• Diameter: \( d=\frac{C}{\pi}\approx\frac{556}{3.14}\approx177.07 \) feet.
• Radius: \( r=\frac{d}{2}\approx\frac{177.07}{2}\approx88.53 \) feet.

Step4: Magnifying glass (d = 5.2 cm)

• Radius: \( r=\frac{d}{2}=\frac{5.2}{2}=2.6 \) cm.
• Circumference: \( C=\pi d\approx3.14\times5.2 = 16.328 \) cm.

Step5: Car tire (C = 71.6 in)

• Diameter: \( d=\frac{C}{\pi}\approx\frac{71.6}{3.14}\approx22.80 \) inches.
• Radius: \( r=\frac{d}{2}\approx\frac{22.80}{2}=11.40 \) inches.

Answer:

Object	Radius	Diameter	Circumference
Circular pond	≈88.53 feet	≈177.07 feet	556 feet
Magnifying glass	2.6 cm	5.2 cm	16.328 cm
Car tire	≈11.40 inches	≈22.80 inches	71.6 inches