Therefore, the difference of arc measures
is
![\( 80^\circ - 24^\circ = 56^\circ \).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/tbzllbeqo322g0vyankhcanz0dk63eodnq.png)
To solve this problem, we'll use the fact that the angle formed by two secants intersecting outside of a circle is equal to half the difference of the measures of the arcs that the secants intercept.
Given:
- The measure of angle
![\( ABC = 28^\circ \)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/2za50rdvm2w2z1vebhcf0tpe0lxak862v0.png)
- The measure of arc
![\( \overset{\frown}{AC} = 80^\circ \)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/dox234gnfe03m9ih9v7v98k57iapflmjj9.png)
- The measure of arc
![\( \overset{\frown}{DE} = 24^\circ \)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/47yrx59engp9o6qxbpx820wzozdmpkyog6.png)
The formula to find the angle formed by two intersecting secants is:
![\[ m \angle ABC = (1)/(2) (m \overset{\frown}{AC} - m \overset{\frown}{DE}) \]](https://img.qammunity.org/2021/formulas/mathematics/middle-school/l87rm9ei78kt2iic87tp2oz3l5mtceggp4.png)
Now, we can calculate step by step:
1. Substitute the given values into the formula:
![\[ 28 = (1)/(2) (80 - m \overset{\frown}{DE}) \]](https://img.qammunity.org/2021/formulas/mathematics/middle-school/y7u78isvzku3h8o7pfomtyiz3gygk2bgm6.png)
2. Double both sides to eliminate the fraction:
![\[ 56 = 80 - m \overset{\frown}{DE} \]](https://img.qammunity.org/2021/formulas/mathematics/middle-school/6k5p3rx8fmt9am8juz9m0wtchd20ql9nzt.png)
3. Solve for
![\( m \overset{\frown}{DE} \):](https://img.qammunity.org/2021/formulas/mathematics/middle-school/m0a8h6iu2r80cemwlzrbs38c4yi7ewjfka.png)
![\[ m \overset{\frown}{DE} = 80 - 56 \]](https://img.qammunity.org/2021/formulas/mathematics/middle-school/jdymdximt7wj3qpwqn5ww5tfg7g07z8xmb.png)
![\[ m \overset{\frown}{DE} = 24^\circ \]](https://img.qammunity.org/2021/formulas/mathematics/middle-school/pirmi3wr9pbts7m2zuvz8foxccb4676sbc.png)
Since
is already given as
the calculation confirms that the given values are consistent with the properties of intersecting secants.
Therefore, the difference of arc measures
is
![\( 80^\circ - 24^\circ = 56^\circ \).](https://img.qammunity.org/2021/formulas/mathematics/middle-school/tbzllbeqo322g0vyankhcanz0dk63eodnq.png)