A -8 hope this helps good luck !
Step-by-step explanation:
(n-2)×180=3420
180n-360=3420
180n=3420+360
180n=3780
n=3780/180
n=21
that is, the number of sides is 21
to get the size of each exterior angle=
360/21
=17.14°
The given distance of 5.20 would be A.
Replace A with 5.20 to solve for T.
T = 5.20^3/2
T = 11.9 years.
Sinx=1/2
sin30=1/2
therefore x=30 degree