The equation this is correct regarding the measure of ∠1 where two secants intercepted is m∠1 = 1 / 2 (b - d)
What is a secant?
Secant is a line that intersects a curve at a minimum of two distinct points.
The two secant intersect outside the circle.
Therefore, if two secants intersect outside a circle, then the measure of the angle formed is one-half the positive difference of the measure of the intercepted arc.
Hence, the required equation is as follows:
m∠1 = 1 / 2 (b - d)
learn more on circle theorem here: https://brainly.com/question/12446309
