Parts of a circle
Illustrate and name parts of circles, including radius, diameter, and circumference; know that the diameter is twice the radius
Lesson
Set out your lesson
“Parts of a circle means practising the idea at the table with counters or paper models and one clear check. We will demo once, then your child tries.”
Bring to the table
- Paper shapes or a ruler and pencil
- Shape name cards
Extra for the adult
Worked example. A rectangle has four right angles. Naming the property is the check.
Optional challenge. For Parts of a circle, add one harder example after success.
What to notice. Keep one parent note: examples tried; results; support used. This session samples Parts of a circle, not mastery.
Share and support
Family records and proof options
Keep a record of your learning
Save photos, notes, and attendance. Export a proof packet for compliance or portfolio reviews.
Practice this concept
Start practiceParts of a circle practice
Practice key ideas from Parts of a circle.
Free · no login · no ads · Practice answers and completion are not saved. Parent observation remains the lesson record.
Learning resources
Extra practice links — they do not replace Gakuva’s teaching approach.
PhET Interactive Simulations · Practice link — not the full lesson
Area Builder
Before you open · source notes
Area Builder supports hands-on exploration for Parts of a circle. Not every lab worksheet.
Free interactive page, no sign-in required for the tested path.
Before you openAsk the learner what they changed in the sim or page and what they observed.
Opening this link does not save learning or assess mastery.
Source, access and review notes
Public PhET Interactive Simulations page. An anonymous GET on 2026-11-12 returned HTTP 200 with no login or payment prompt for this URL. Opening the link does not save practice or assess mastery. An adult should preview and guide the learner.
PhET Interactive Simulations. “Area Builder.” External page; Gakuva does not copy, host, embed, or redistribute materials.
Unknown — link only
Check understanding
- Label the radius, diameter, and circumference on a circle diagram
- Calculate the diameter given a radius of 4.5 cm (diameter = 9 cm)
- Explain the relationship between radius and diameter in their own words
“If you give your child a round plate and a ruler, can they measure the diameter — and explain how the radius compares to the diameter?”
Curriculum record
- Type
- Conceptual
- Subject
- Mathematics
- Domain
- Geometry
- Age range
- Ages 10–13
Standards