11.3. Prisms http://www.ck12.org
- Find the volume of the regular hexagonal prism below.
- Find the area of the oblique prism below.
Answers:
- For this prism, each lateral face has an area of 160units^2. Then, we need to find the area of the regular pentagonal
bases. Recall that the area of a regular polygon is^12 asn.s=8 andn=5, so we need to finda, the apothem.
tan 36◦=4
a
a=4
tan 36◦≈ 5. 51
SA= 5 ( 160 )+ 2
(
1
2
· 5. 51 · 8 · 5
)
= 1020. 4
- A rectangular prism can be made from any square cubes. To find the volume, we would simply count the cubes.
The bottom layer has 20 cubes, or 4 times 5, and there are 3 layers, or the same as the height. Therefore there are 60
cubes in this prism and the volume would be 60units^3.