what is length of cord on 3.875 dia circle with 3 point equally spaced at 120 degrees

Question

Bolt circle of 3.875 dia has 3 equally spaced holes at 120 degrees apart. what is the distace from center to center the hole

Answer 1

sound tu me like yu hav equilateral triangel inside serkel

serkel diam=3.875, so radius=1.9375

polygon (triangel) side leng=3.3558...distans from hole-tu-hole

triangel...all 3 angels=60

draw vertikal line thru serkel senter & put top av triangel at top weer this hit serkel

get 2 identikal rite triangels...30/60/90

from trig funks, yu find:inside serkel radius=(1/2) outside serkel radius

hite av triangels=(inside radius) + (outside radius)

or yuze triangel side leng=2*(outside radius)*(kosine beta)

alfa= apex angel=360/n=360/3=120deg

beta=(180-alfa)/2=30 deg