Difference between revisions of "1985 AIME Problems/Problem 15"

(See also)
(problem and solution)
Line 1: Line 1:
 
== Problem ==
 
== Problem ==
 
+
Three 12 cm  12 cm [[square (geometry) | squares]] are each cut into two pieces <math>A</math> and <math>B</math>, as shown in the first figure below, by joining the [[midpoint]]s of two adjacent sides. These six pieces are then attached to a [[regular polygon | regular]] [[hexagon]], as shown in the second figure, so as to fold into a [[polyhedron]]. What is the [[volume]] (in <math>\mathrm{cm}^3</math>) of this polyhedron?
 
== Solution ==
 
== Solution ==
 
+
Note that gluing two of the given polyhedra together along a hexagonal face (rotated <math>60^\circ</math> from each other) yields a [[cube (geometry) | cube]], so the volume is <math>\frac12 \cdot 12^3 = 864</math>.
 
== See also ==
 
== See also ==
 +
* [[1985 AIME Problems/Problem 14 | Previous problem]]
 
* [[1985 AIME Problems]]
 
* [[1985 AIME Problems]]
 +
 +
[[Category:Intermediate Geometry Problems]]

Revision as of 19:23, 1 December 2006

Problem

Three 12 cm 12 cm squares are each cut into two pieces $A$ and $B$, as shown in the first figure below, by joining the midpoints of two adjacent sides. These six pieces are then attached to a regular hexagon, as shown in the second figure, so as to fold into a polyhedron. What is the volume (in $\mathrm{cm}^3$) of this polyhedron?

Solution

Note that gluing two of the given polyhedra together along a hexagonal face (rotated $60^\circ$ from each other) yields a cube, so the volume is $\frac12 \cdot 12^3 = 864$.

See also