Question 43
LociA particle P moves between points S and T such that angle SPT is always constant. Find the locus of P.
- A.It is a semi-circle with ST as diameter.
- B.It is a perpendicular bisector of ST.
- C.It is a quadrant of a circle with ST as diameter.
- D.It is a straight line perpendicular to ST.
Show the answer and explanation
Answer: A (It is a semi-circle with ST as diameter.)
Explanation
Points that see ST at a fixed angle lie on a circular arc through S and T; of the choices, the semicircle on ST as diameter is the arc (the case where the angle is 90°).