Triangle with angles

• At first, choose the mode New point (see 3.2) in the toolbar and click three times on the drawing pad to create the three vertices A, B and C of the triangle.

• Select the mode Polygon and click on the points A, B, C and again A to create the triangle P. In the algebra window the area of the triangle is shown.

• To get all the angles of our triangle, choose the mode Angle in the toolbar and click on the triangle.

Now, choose the Move mode and drag the vertices to change the triangle dynamically. If you don't need the algebra window and coordinate axes, hide them by using the View menu.