Answer:
Option B - right angle
Step-by-step explanation:
We have Given statement : To trisect a(n) ____ angle, you first construct an equilateral triangle.
Solution: Option B is correct because, a right angle is 90 degrees and an equilateral triangle has a 60 degree corner.
So, if you construct the equilateral you have one 60 and one 30, now bisect the 60.