Answer:
90
Explanation:
From the given drawing, we have;
ΔRST is circumscribed about circle A
The center of the circle A = The point A
The line RT = A tangent to the circle A
The radius to the circle A = The line AP
According to circle theory, a line which is tangent to a circle is perpendicular to the radius of the circle drawn from the point of tangency
Where two lines are perpendicular to each other, then the angle formed between them = 90°
The angle formed between a tangent and the radius of the circle = m∠APT
Therefore;
m∠APT = 90°