Download LATERAL FACES

12-1 PRISMS
Prism a 3d solid with the following:
BASES – congruent polygons
in parallel planes
ALTITUDE– a segment
joining the two bases and
 to both (length of altitude is
the height of the prism)
LATERAL FACES – the faces
that are not bases
(always parallelograms)
LATERAL EDGES – the parallel segments
joining the lateral faces
If the lateral faces of a prism are
rectangles, then the prism is a right
prism.
If the lateral faces of a prism are not
rectangles, then the prism is oblique.
(see pg. 475)
Prisms are named by the shape of
their bases.
Triangular prism, rectangular
prism, pentagonal prism.
The LATERAL AREA (LA) of a
prism is the sum of the areas of
the lateral faces of the prism.
The TOTAL AREA (TA) is the
sum of all of the prism’s faces
(lateral area plus the sum of the
bases of the prism).
TA=LA +2B
THM 12-1
The Lateral area of a RIGHT prism equals the
perimeter of a base times the height of the prism.
LA=Ph
THM 12-2
The VOLUME of a RIGHT prism equals the area
of a base times the height of the prism.
V=Bh
LA = 120 u
2
TA= 180 u
4
12
5
2
V= 120 u
3
LA = 48 u
2
2
TA= 80+4 3u
60
3
2
4
V= 96+12 3u
3
LA =
TA=
100 u 2
5
2
8
132 u 2
V=
80 u
3