which equation is correct regarding the measure of ∠1?\n○ (mangle1=\frac{1}{2}(a - c))\n○ (mangle1=\frac{1}{2…

which equation is correct regarding the measure of ∠1?\n○ (mangle1=\frac{1}{2}(a - c))\n○ (mangle1=\frac{1}{2}(a + c))\n○ (mangle1=\frac{1}{2}(b - d))\n○ (mangle1=\frac{1}{2}(b + d))

which equation is correct regarding the measure of ∠1?\n○ (mangle1=\frac{1}{2}(a - c))\n○ (mangle1=\frac{1}{2}(a + c))\n○ (mangle1=\frac{1}{2}(b - d))\n○ (mangle1=\frac{1}{2}(b + d))

Answer

Explanation:

Step1: Recall the secant - secant angle formula

The measure of an angle formed by two secants intersecting outside a circle is half the positive difference of the measures of the intercepted arcs. Let the measures of the intercepted arcs be $b$ and $d$ where $b>d$. The formula for the measure of the angle $\angle1$ formed by the two secants is $m\angle1=\frac{1}{2}(b - d)$.

Answer:

$m\angle1=\frac{1}{2}(b - d)$