Question

unit 3 lesson 3- practice problems

1. diego measured the diameter and circumference of several circular objects and recorded his measurements in the table.

object	diameter (cm)	circumference (cm)
flying disc	23	28
jar lid	8	25
flower pot	15	48

one of his measurements is inaccurate. which measurement is it? explain how you know.

Explanation:

Step1: Recall circumference formula

Circumference $C = \pi d$ (≈3.14d)

Step2: Calculate expected C for each object

• Half dollar: $3×3.14≈9.42$ (close to 10)
• Flying disc: $23×3.14≈72.22$ (≠28)
• Jar lid: $8×3.14≈25.12$ (close to 25)
• Flower pot: $15×3.14≈47.1$ (close to 48)

Step3: Identify mismatch

Flying disc's C is too low.

Answer:

The flying disc's circumference measurement (28 cm) is inaccurate. For a diameter of 23 cm, the expected circumference is about 72.22 cm (using $C≈3.14d$), which is much larger than 28 cm. All other objects have circumferences close to the expected values from the formula.