The segment is referred to as a diameter
I think this attachment will help you
Answer:
x=3
Step-by-step explanation:
Because it is equilateral, all the sides are equal. so you can make your equation
3(2x-3)=21
Distribute the 3 throughout, giving you 6x-3=21
Subtract the 3 from both sides, and you are left with 6x=18
Divide 18 by 6 and you get 3.