Triangular data fetch from sqlite in ios

i have current lat,long and find 2 lat,long in a circle in the radius 2. this is my query to find points between a triangle

select place
from TBL_Locations
where 
((lat between 8.563041 and 8.560707) OR (lat between 8.560707 and 8.560718) OR (lat between 8.560718 and  8.563041)) 
AND 
((lon between 76.882511 and 76.883874) OR (lon between 76.883874 and 76.881248) OR (lon between 76.881248 and 76.882511)) 

but if i try to find points with radius 3 and use this query i didnt get points with radius 2. I think this only get points from a line not in a triangular method. Any help