Knowledge point 1

Formula derivation of arc length and sector area

1. 1

Basic calculation of arc length and sector area

Arc length formula:

Sector area formula:

Exercise 1. 1

1.2

Geometric application of arc length and sector area

Exercise 1.2

answer

Exercise 1. 1

1、B

2、3π

3、 150

4。 B

5、3π

6。 25

7、C

8。 4π

9、B

Exercise 1.2

1、20

2、C

3、

4、8π

5、

6。

7.

8.