Question

from unit 3, lesson 10
jada is making circular birthday invitations for her friends. the diameter of the circle is 12 cm. she bought 180 cm of ribbon to glue around the edge of each invitation.
how many invitations can she make?

Explanation:

Step1: Calculate circumference of one circle

The formula for the circumference of a circle is \( C = \pi d \), where \( d \) is the diameter. Given \( d = 12 \) cm, so \( C=\pi\times12\approx3.14\times12 = 37.68 \) cm.

Step2: Divide total ribbon by circumference

Total ribbon is 180 cm. Number of invitations \( n=\frac{180}{37.68}\approx4.77 \). Since we can't make a fraction of an invitation, we take the whole number part, so \( n = 4 \).

Answer:

4