Geometry
7 Online
OpenStudy (loner2345):
Picture in the comments and please help
Find the area if the figure to the nearest hundredth of a centimeter.
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OpenStudy (loner2345):
OpenStudy (loner2345):
@jim_thompson5910
jimthompson5910 (jim_thompson5910):
you can break up the hexagon into 6 triangles like this
jimthompson5910 (jim_thompson5910):
each triangle is an equilateral triangle with side 1.5
jimthompson5910 (jim_thompson5910):
are you able to find the area of each triangle?
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OpenStudy (loner2345):
Yes? Do times or add 1.5 together? or??
jimthompson5910 (jim_thompson5910):
Area of Equilateral Triangle
\[\Large A = \frac{\sqrt{3}}{4}*s^2\]
A = area
s = side length
jimthompson5910 (jim_thompson5910):
A is unknown, s = 1.5
OpenStudy (loner2345):
Where do I go from there?
jimthompson5910 (jim_thompson5910):
what area did you get?
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OpenStudy (loner2345):
2.25 ? @jim_thompson5910
jimthompson5910 (jim_thompson5910):
1.5^2 = 2.25
now multiply that by the square root of 3 over 4
jimthompson5910 (jim_thompson5910):
\[\Large A = \frac{\sqrt{3}}{4}*s^2\]
\[\Large A = \frac{\sqrt{3}}{4}*1.5^2\]
\[\Large A = \frac{\sqrt{3}}{4}*2.25\]
\[\Large A = ???\]
OpenStudy (loner2345):
5.1? I don't have a calculator with the square root symbol @jim_thompson5910
jimthompson5910 (jim_thompson5910):
use this
http://web2.0calc.com/
for square roots, you need to type in `sqrt`
example: type in `sqrt(7)` to mean \(\Large \sqrt{7}\)
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jimthompson5910 (jim_thompson5910):
so in your case, you'll type in `sqrt(3)/4*2.25`
OpenStudy (loner2345):
1.7?
OpenStudy (loner2345):
@jim_thompson5910
jimthompson5910 (jim_thompson5910):
jimthompson5910 (jim_thompson5910):
I'm getting 0.9742785792574935
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jimthompson5910 (jim_thompson5910):
the area of ONE triangle is 0.9742785792574935
but there are 6 of these triangles total
OpenStudy (loner2345):
can't we round that to 10? and wouldn't it be 10*6?
jimthompson5910 (jim_thompson5910):
0.97 wouldn't round to 10
jimthompson5910 (jim_thompson5910):
I think you mean 1.00?
jimthompson5910 (jim_thompson5910):
I wouldn't round just yet
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jimthompson5910 (jim_thompson5910):
0.9742785792574935*6 = ???
use the calculator. Type in `0.9742785792574935*6` or copy/paste it in
OpenStudy (loner2345):
5.845671476
OpenStudy (loner2345):
@jim_thompson5910
jimthompson5910 (jim_thompson5910):
good
jimthompson5910 (jim_thompson5910):
so that takes care of the hexagon portion
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jimthompson5910 (jim_thompson5910):
now focus on the semicircle portion in blue
see attached
jimthompson5910 (jim_thompson5910):
what is the area of that blue semicircle?
OpenStudy (loner2345):
8.768507213?
jimthompson5910 (jim_thompson5910):
what did you type in to get that?
OpenStudy (loner2345):
my answer up top times 1.5
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jimthompson5910 (jim_thompson5910):
the semi-circle has a radius of 1.5/2 = 0.75
use the area of a semi-circle formula
\[\Large A = \frac{\pi*r^2}{2}\]
OpenStudy (loner2345):
0.883572934 thats what my calculator says
jimthompson5910 (jim_thompson5910):
mine too
OpenStudy (loner2345):
Yayyyyyyy!!!!!
jimthompson5910 (jim_thompson5910):
area of hexagon = 5.845671476
area of semicircle = 0.883572934
add the two areas to get the overall figure area
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OpenStudy (loner2345):
A= 6.72924441
OpenStudy (loner2345):
@jim_thompson5910
OpenStudy (loner2345):
For part C it says suppose each side length was multiplied by 3. What would be the area of the new figure?
OpenStudy (loner2345):
@jim_thompson5910
jimthompson5910 (jim_thompson5910):
`each side length was multiplied by 3`
so the new area would be 9 times larger
3^2 = 3*3 = 9
new area = 9*(old area)
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OpenStudy (loner2345):
Okay, so it would be 9* 6.72924441= 60.56319969
jimthompson5910 (jim_thompson5910):
yes
OpenStudy (loner2345):
Yayy! Thank you!
jimthompson5910 (jim_thompson5910):
yw