Small Geogebra applet to show that angle at semi-circle is a right angle.[br][b][color=#ff0000]Objective : To establish the relation that angle at semi-circle is a right angle.[/color][/b][br][b][u][color=#0000ff]Instructions To Use.[/color][/u][br][/b]1) Move the point A on both semi-circles and observe ∠BAC . It always remains 90° .[br]2) Move the diameter BC and Observe ∠ BAC. It always remains 90°.[br]3) Draw a conclusion that angle at semi-circle is a right angle.[br][br][br][br][br][br][br]

By Mahanth Chaudhary[br]Mathematics Teacher and Trainer