Crossed Ladders Problem
Given two crossed Ladders resting against two buildings, what is the distance between the buildings? Letthe height at which they cross be 
and the lengths of the Ladders 
and 
. The height at which touches the building 
is then obtained by solving
Call the horizontal distance from the top of
to the crossing 
, and the distance from the top of , 
. Callthe height at which touches the building 
. There are solutions in which , , , , , and are allIntegers. One is 
, 
, 
, and 
.See also Ladder
References
Gardner, M. Mathematical Circus: More Puzzles, Games, Paradoxes and Other Mathematical Entertainments from Scientific American. New York: Knopf, pp. 62-64, 1979.
- Set Difference
- Set Partition
- Set Theory
- Sexagesimal
- Sexdecillion
- Sextic Equation
- Sextic Surface
- Sextillion
- Sexy Primes
- Seydewitz's Theorem
- Sgn
- Shadow
- Shadowing Theorem
- Shafarevich Conjecture
- Shah Function
- Shah-Wilson Constant
- Shallit Constant
- Shallow Diagonal
- Shanks' Algorithm
- Shanks' Conjecture
- Shannon Entropy
- Shannon Sampling Theorem
- Shape Operator
- Shapiro's Cyclic Sum Constant
- Sharing Problem