What is the locus of a point P which moves on one side of a straight line XY, so that the angle XPY is always equal to 90o?

A.

the perpendicular bisector of XY

B.

a right-angled triangle

C.

a circle

D.

a semi circle

Correct answer is D

Since XY is a fixed line and

XPY = 90o P is on one side of XY

P1P2P3......Pn are all possible cases where

XPY = 90o the only possible tendency is a semicircle because angles in semicircle equals 90o