Circle areaDiameter given
Name: Date:
Find the area of each circle. Use π = 3.14.
1 cm²
2 cm²
3 cm²
4 cm²
5 cm²
6 cm²
7 cm²
8 cm²
Area of a circle from the diameter worksheets
The area formula wants the radius, and every circle here hands you the diameter instead — so halving is the fixed first move, done before anything else. These free printable worksheets drill exactly that step, with pi = 3.14 throughout.
Kid stuck on one? You don’t just get the sheet.
Area of a circle from the diameter
The answer key prints on a separate page.
What's on this sheet
The mixed area sheets alternate radius and diameter so a child has to read each figure; this one is diameter every time, because skipping the halve is the single most common error on this topic and a page that repeats the same first move is where the habit is built. The number sits on a chord across the middle, and the work is to halve it before touching the formula.
Why this sheet works
Area squares the radius, so a diameter used where the radius belongs is not a little wrong — it is four times too big. That is why the halve comes first and stands on its own: square the wrong number and the whole answer is off by a factor of four, with nothing later to catch it.
How this one works
One question from this sheet, worked through a step at a time.
Area of a circle marked 16 cm
- The 16 cm marked here goes right ACROSS the circle — it is the diameter, not the radius. The area formula wants the radius, so that is the first thing to sort out.
- Half of 16 is 8, so the radius is 8 cm. Skipping this step is what makes an area come out four times too big.
- Area is π × r × r. Square the RADIUS first — only the r is squared, not the π with it: 8 × 8 = 64.
- Then multiply by π: 64 × 3.14 = 200.96 square cm.