646

the inward ^ /reflecting/ concaue = 180 = Aa
outward Reflecting foyld concaue = 60 = ax or 6x

[radi]us of the inward concaue side a diam = &/2. 1/2 or 3 Radij

180 3 ____ 540

3 5/10
3 1/4
3
2 1/2

Ref: CELL/RS/HF_s43  © Centre for Editing Lives and Letters