Answer:
t=11,11 days
Step-by-step explanation:
F=frogs poblation, t=time, be the variables dF/dt = KF, dF/F=Kdt, integrating
⇒ LnF=Kt+c,
; Knowing t=0, F=17 and t=6 F=51 (tripling every 6 days (17*3)),
⇒
, so
, now if F=130, t=? we have:

X/35 = 100...multiply both sides by 35
x = 100 * 35
x = 3500
The area of a triangle is A = (b*h)/2:
(5 * 8)/2 = 20