Number of angles = number of sides
180 - 120 = 60 (calculating the exterior angle)
360 / 60 = 6
There are 6 sides.
Hope this helps! :)
Answer:
452.45mmm^2
Step-by-step explanation:
Step one:
Given data
outer radius R= 20mm
inner radius r= 16mm
let us find the area of the outer circle
Area= πR^2
Area= 3.142*20^2
Area= 3.142*400
Area= 1256.8 mm^2
let us find the area of the inner circle
Area= πr^2
Area= 3.142*16^2
Area= 3.142*256
Area= 804.35 mm^2
Hence the area of the section is
Area of outer- Area of inner
=1256.8-804.35
=452.45mmm^2
SA=2hpir+2pir^2=2pir(h+r)
V=hpir^2
SA=339
r=6
339=2pir(h+r)
339=2pi3(h+3)
339=6pi(h+3)
divide both sides by 6pi
56.5/pi=h+3
minus 3 both sides
(56.5/pi)-3=h
(56.5-3pi)/pi=h
v=hpir^2
v=((56.5-3pi)/pi)(pi)(6)^2
v=(56.5-3pi)(36)
v=2034-108pi
use pi=3.141592
v=1694.7079934123023302460345146058
round
1695 cubic cm
12 x 4.89 = 50.68
17 x 4.72 = 80.24
15 x 5.09 = 76.35
50.68 + 80.24 + 76.35 = $207.27
