Pentagonal pyramid

The height of a regular pentagonal pyramid is as long as the edge of the base, 20 cm. Calculate the volume and surface area of the pyramid.

Correct answer:

V =  4587.9397 cm3
S =  1902.113 cm2

Step-by-step explanation:

a=20 cm h=a=20 cm n=5  r=1025+10 5 a=1025+10 5 2013.7638 cm  S1=425+10 5 a2=425+10 5 202688.191 cm2  V=31 S1 h=31 688.191 20=4587.9397 cm3
h2=r2+h2=13.76382+20224.2784 cm  S2=2a h2=220 24.2784242.7844 cm2  S=S1+n S2=688.191+5 242.7844=1902.113 cm2



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Showing 1 comment:
Sebf
Thanks for the demonstration.
All my respect.
Regards.
S.





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