2.3 Calculate the area of a circle and parts of a circle with a calculator

• Mathematics
• Lower Secondary (Key Stage 3)

Calculate the area of a circle and parts of circle

Which part of the circle are we talking about when we use the term 'circumference'?

Which part of the circle are we talking about when we use the term 'radius'?

Which part of the circle are we talking about when we use the term 'centre'?

Which part of the circle are we talking about when we use the term 'diameter'?

What is the diameter of a circle if its radius is 6cm?

1. 3cm
2. 12cm
3. 10cm
4. 12mm

What is the radius of a circle if the diameter is 16m

1. 16cm
2. 3m
3. 8m
4. 8cm

What is the circumference of a circle with a radius of 3cm?
(Remember C=2πr, where π=3.14)

1. 16.85cm
2. 19.85cm
3. 17.85cm
4. 18.85cm

What is the circumference of a circle with a diameter of 10cm?
(Remember C=2πr, where π=3.14)

1. 30.42cm
2. 31.42cm
3. 32.42cm
4. 33.42cm

2.3 Calculate the area of a circle and parts of a circle with a calculator

What is a 'sector' of a circle?

Activity

More practice for finding the area of a circle

https://miro.com/welcomeonboard/WVV4SEpDZTNzdEtOd3g4WU1VUk9leVVWVHRkMHdUaFJRaFJJOGQ5eGE4dkQyRldiZHhSallmSzYyUWFRUGc4TXwzNDU4NzY0NTUzNjIyODU4ODU4fDI=?share_link_id=78621385462

Practice for finding the area of a sector of a circle

https://miro.com/welcomeonboard/N2VvMDJTeDVqRDhLY1k3QkRFdEtJRUxzQ1JoRTBJMmxyVG5kMUxZTkUyOXhFN2l4STVPNUJmS0pXN3I5bkpwOXwzNDU4NzY0NTUzNjIyODU4ODU4fDI=?share_link_id=488193677518

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.

Partial circle area and arc length

Activity

Circumference of parts of circles

https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-area-circumference/e/circumference-of-parts-of-circles

Area of parts of circles

https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-geometry/cc-7th-area-circumference/e/area-and-circumference-of-parts-of-circles