Magnetic Field due to Circular Loop of current, is a falls statement

Circular loop states that the Tangent ANGLE IS 90 DEGREE. That means 'Odl' is PERPENDICULAR to 'AB'. & So is 'Odl' perpendicular to 'CD' that means it is 90 Degree

NOW CHECK THE PRESENTATION1 IN MY ATTACHMENTS OR OPEN NEXT LINK

circular loop DIAGRAM as we think

There is three slides shown
NOW CONSIDE "dl" AS 'B' AND 'C'. THEN CONSIDER POINT 'P' ALSO NOW IF ANGLE 'B' AND 'C' IS 90 DEGREE THEN WHAT WILL BE THE DEGREE OF ANGLE P IS IT '0' OR LESS THAN THAT.
AS B+C ALREADY REACHES 180DEGREE

2 PERPENDICULAR LINE FROM A COMMON LINE AT A SPECIFIED DISTANCE WILL NEVER MEET AT ANY POINT HOWEVER IT IS EXTENDED AND THE DISTANCE BETWEEN C&B WILL BE THE SAME AT A&D, IF 'AB' ='CD'.(CHECK SLIDE 2 IN PRESENTATION1)

DIAGRAM IN THE SLIDE 1 WILL BECOME LIKE DIAGRAM IN SLIDE 2, SINCE ANGLE 'dlP' is perpendicular to 'Odl'.