Answer:
64°
Explanation:
The triangle is an isosceles triangles (both legs are equal to the radius of the circle), so that means the base angles are the same.
Angles of a triangle add up to 180°, so:
128 + 2x = 180
2x = 52
x = 26
∠1 is complementary to the base angle, so:
∠1 = 90 − 26
∠1 = 64
