Calculating the Radius of an Arc
Q
UITE OFTEN,WHEN DESIGNINGa curved cabinet or tabletop, you
need to determine the radius of an arc that will give you a spe-
cific amount of convexity (height of arc) and also fit within a specified
width. Here’s a formula for calculating the radius of an arc that must
pass through three predetermined points. With it you can find the ra-
dius (R) from the desired width (A) and height (B) as defined by the
three points, shown below. The formula is:
R = ___________(A/2)^2 + B^2
2B
CHAPTER SIX
Desired width, A
Point 1
Arc
Desired
height, B
Point 3
Radius, R,
determined
by formula
Point 2