Question

prove that the angle in the semicircle is right angle

Answer 1

given:a straight line A and B
construction: draw a perpendicular bisector of a line and name it as OC
name the first angle x and the other angle as x
proof:
x+x=180°
now consider the two angles as 90°,now
2x=180°
x=(180/2)°
x=90°
hence proved