Question

in given figure if pqr is a tangent to the circle at q whose centre isbo and ab is chord parallel to pr such that |_pqr=70°, find the|_aqb

Answer 1

40 degree is the answer,
Angle ABQ = 70, ( alternative angle)
Angle QAB = 70 ( alternate segments) so angle QAB = angle BQR
In triangle ABQ, by ASP
ABQ + QAB + AQB = 180
Angle AQB =, 40 degree

Answer 2

we have a therom that is if a tangent at any point of a circle is perpendicular to the radius through the point of contact. so
pr is a tangent.
oq perpendicular on pr.
so oqr +oqp = 180
oqr = oqb + bqr
90 = oqb+ 70
oqb = 20 .
same as oqa = 20
abq = 40 .
I hope my answer is wright and its helpful for you.