Mrs.D Math · 7th Grade

π

PI RUN

Circumference of a Circle

C = π × d

C = 2 × π × r

◯ Find Circumference

🔍 Find r or d

📚 Word Problems

🎲 Mixed

◯ Find Circumference

🔍 Find r or d

📚 Word Problems

🎲 Mixed

📺 Mrs.D Math Lesson

Watch on YouTube ↗

Made for Mrs.D Math students 🎉

◯ Circumference

The Two Formulas

C=πd

Use when given diameter: C = π × d

d = 10 → C = π × 10 = 10π • or using 3.14: C = 3.14 × 10 = 31.4

C=2πr

Use when given radius: C = 2 × π × r

r = 5 → C = 2 × π × 5 = 10π • or: C = 2 × 3.14 × 5 = 31.4

Finding r or d from C

d

d = C ÷ π • If C = 10π: d = 10π ÷ π = 10 • If C = 31.4: d = 31.4 ÷ 3.14 = 10

r

r = C ÷ (2π) • If C = 10π: r = 10π ÷ (2π) = 5 • If C = 31.4: r = 31.4 ÷ 6.28 = 5

Difficulty Levels

🌿

Easy — Leave answers in terms of π (e.g. 6π cm). Find r and d from nπ circumferences.

🔥

Medium — Calculate using π ≈ 3.14 for decimal answers. Find r and d from decimal circumferences.

💎

Hard — Larger values, real-world word problems, using π ≈ 3.14.

Score

0

Streak ⚡

0

Lives

❤️❤️❤️

Easy

QUESTION 1 / 10

FIND CIRCUMFERENCE

📺 Mrs.D Math Lesson

Watch on YouTube ↗

π

Easy Level

PI RUN COMPLETE!

Great work!

Your Results

0

points

0

Correct

0

Wrong

0

Best Streak

Made for Mrs.D Math students 🎉

📋 Answer Review

Easy Level

All questions

Made for Mrs.D Math students 🎉