Why is line AL equal to BC?
Because the point B is the center of the circle CGH, Definition 11 tells us that BC is equal to BG. next
![](p2a.gif)
Because D is the center of the circle GKL, DL is equal to DG. next
![](p2b.gif)
Since ADB is an equilateral triangle, DA and DB are equal . next
![](p2c.gif)
By axiom 3, the remainder AL is equal to the remainder BG. next
![](p2d.gif)
But BC is equal to BG, so AL is equal to BC by axiom 1. next
![](p2e.gif)
Therefore the straight line AL is equal to BC Back to Start