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°
44
simply because it asks what the heaviest is
1. is the third choice
2. is second choice
3. is fourth choice
Well, since 3/15 can be simplified to 1/5 by dividing the top and the bottom by 3, you would just need to find the decimal of 1/5 which is much more commonly recognized. it's .2 (becasue 1/10 would be .1 and 1/5=2/10 so .1x2=.2)