Answer:
19.8
Step-by-step explanation:
(whole secant) x (external part) = (tangent)^2
The whole secant is d+17 where d is the diameter
External part is 17
Tangent is 25
(d+17) *17 = 25^2
17d+17^2 = 25^2
17d +289=625
Subtract 289 from each side
17d +289-289=625-289
17d =336
Divide each side by 17
17d/17 = 336/17
d = 19.76470588
Rounding to the nearest tenth
19.8
