Area and perimeter of circle

How to reach the area and circumference of a circle in GeoGebra can be done in several ways.

Construct the circle first

1. Construct the first circle using. eg 'circle out from the center and point'--button.
2. Press 2 places on the drawing pad.
3. Thus you have now 1 circle on the drawing pad, which is made from 2 points A and B.

Method #1 – Input-feltet

Area

1. I input-feltet skal du starte på at skrive areal …
2. Now select the area[ <Polygon> ]
3. Pressure circle name / letter

   Area[c]

4. Press Enter on your keyboard.
5. In Algebra window is now through variable a, what area is.

Circumference

1. I input-feltet skal du starte på at skrive omkreds…
2. Now select the Circumference[ <Conic> ]
3. Pressure circle name / letter

   Circumference[c]

4. Press Enter on your keyboard.
5. In Algebra window is now through the variable b, what is the circumference.

Method #2 – Værktøjsbjælken

Area

1. Select the tool area--button.
2. Press the circle periphery.
3. Now the area of ​​the circle on the drawing pad.

Circumference

1. Select the tool length--button.
2. Press the circle periphery.
3. Now the circumference of the circle on the drawing pad.

Test

Now try to pull the point A or point B. Notice, what happens to the circle area and perimeter.

Video