the reciprocal trig functions on the unit circle

use the slider to change the angle in steps of 5 degrees
How can we be sure that the lengths marked are what they claim to be? Tangere is Latin for the present active infinitive of tangō. "to touch, to grasp" (1). Why is the tangent called that? Secāre is the Latin present active infinitive of secō. (2) It means to cut or divide. Why is the secant called that? 1. http://en.wiktionary.org/wiki/tangere 2. http://en.wiktionary.org/wiki/seco#Latin