Area of Circles
Grade 7 · Math · Geometry · Minnesota, USA
Lesson Summary
Use the formula A = πr² to find the area of circles and semicircles.
Explanation
The area of a circle is A = πr², where r is the radius. If you are given the diameter, divide it by 2 to get the radius first. For a semicircle, find the full circle area and divide by 2. The number π (pi) is approximately 3.14. Circle area tells you how much surface a circular shape covers.
Practice Questions
Q1: Find the area of a circle with radius 5 cm. Use π ≈ 3.14.
Answer: A = 3.14 × 5² = 3.14 × 25 = 78.5 cm².
Q2: Find the area of a circle with diameter 12 in. Use π ≈ 3.14.
Answer: Radius = 6 in. A = 3.14 × 6² = 3.14 × 36 = 113.04 in².
Q3: Find the area of a semicircle with radius 8 m. Use π ≈ 3.14.
Answer: Full circle: 3.14 × 64 = 200.96. Semicircle: 200.96 ÷ 2 = 100.48 m².
People Also Ask
What is Area of Circles in Grade 7 Math?+
Area of Circles is a lesson in the Geometry chapter of Grade 7 Math. It is part of the Minnesota, USA school curriculum and covers key concepts that students need to understand at this level.
What grade level covers Area of Circles?+
Area of Circles is taught in Grade 7 as part of the Math curriculum in Minnesota, USA.
How can I help my child with Geometry in Math?+
Start with the lesson summary and explanation on this page. Practice the questions provided, then use TutorTom for personalized, step-by-step help with Geometry topics.