Area and Circumference of Circles

Ask students to circle whether each label is a radius or a diameter before they calculate. Use the circumference page first, then the area page, and the mixed page as a review.

Find the circumference and area of 4 circles from a radius or diameter, like 4 cm and 15 m. The circumference of a circle is the distance around it, C = π × d, and its area is A = π × r × r. The directions on the page read: Find the circumference and area of each circle. Some circles show the radius and some show the diameter. Use 3.14 for π and the work space. Round to the nearest hundredth when needed. An answer key is included.

Yes, both. We made it for 6th Grade geometry, and the page works the same whether it lands on a kitchen table or a center rotation. At home, most families go through it together and talk the answers out loud, and that talking is where most of the learning happens with circumference and area of circles. In class it runs well as independent work while you pull a small group. Print one copy or thirty, whichever the day needs.

The radius goes from the center to the edge, and the diameter goes all the way across through the center. The diameter is twice the radius, so a circle with a 3.5 cm radius has a 7 cm diameter.

Halve the diameter to get the radius, then use A = π × r × r. A circle with a 10 ft diameter has a radius of 5 ft, so its area is 3.14 × 5 × 5 = 78.5 square feet.

Multiply the diameter by pi, or 2 times the radius by pi. With 3.14 for pi, a 9 in diameter gives a circumference of 28.26 in.

Yes. All 3 circle sheets have an answer key.