1, Method 1: Know the diameter of the circle. Calculate the radius of a circle with its diameter: r=d/2, where d is the diameter of the circle. Use the area formula of a circle: area =πr? , where π is pi and r is the radius of a circle.
Substitute π and radius into the formula to calculate the area of the circle. For example, a circle has a diameter of 20cm (0.2m), a radius of 10cm (0. 1m) and an area of =3. 14x0. 1? =0.03 14 square meter.
2. Method 2: Know the radius of the circle. Directly use the area formula of the circle: area =πr? , where π is pi and r is the radius of a circle. Convert the radius from cm to m (if necessary):1cm = 0.01m.
Substitute π and radius into the formula to calculate the area of the circle. For example, if the radius of a circle is 10 cm (that is, 0. 1 m), then the area is =3. 14x0. 1? =0.03 14 square meter. Either way, you need to know the radius or diameter of the circle to calculate the area.
Advantages of learning mathematics
People who are good at math are relatively smart and savvy, and they can show their advantages in dealing with people. The faster you think, the more ways and ideas you have. Mathematics is the foundation of other disciplines, and it is easier for people who learn mathematics well to get into other disciplines. Learning software, computer, finance and other engineering majors is even more handy.
It is used everywhere in life. Nowadays, the society is an information society, and mathematical knowledge is used in financial management and computers. Mathematics can cultivate people's integrity and honesty. Mathematics pays the most attention to convincing people by reasoning, and only believes in the results of logical reasoning. Mathematics can be used to cultivate people's tenacity and courage. Mathematics can cultivate people's overall consciousness. Mathematics can cultivate people's good character.