Is it possible to know a circle's radius just by its secant lengths?

Answer 1

Try it.....draw a circle and then draw 2 secant lines. Then, draw a circle with a different radius and draw secant lines that are either the same total length, or which have the same chord length---or both. You will see that the angle between the secant lines is different.

I think that one secant line of defined length (total and chord), plus the angle to a 2nd secant line, gives a unique solution.

Again--try it....

Answer 2

No, LIna. You need to know something else other than the secant lengths like the angle of the sector formed by the radii from the endpoints of the secant or the height of the segment formed by the secant.