Answer:
AB = 17
Step-by-step explanation:
You want the measure of chord AB = 7y -4, when arc AB is congruent to arc DE subtended by chord DE = 4y +5.
Chords
Chords that subtend congruent arcs (in the same circle) are congruent.
AB = DE
7y -4 = 4y +5 . . . . . equate chord lengths
3y = 9 . . . . . . . . add 4-4y
y = 3 . . . . . . . divide by 3
7y -4 = 7(3) -4 = 17 . . . . . . find the length of AB
The length of chord AB is 17 units.
