20
Part of 2005 AMC 10
Problems(2)
Equiangular Octagon
Source:
1/12/2009
An equiangular octagon has four sides of length and four sides of length , arranged so that no two consecutive sides have the same length. What is the area of the octagon?
(A)\ \frac{7}{2}\qquad
(B)\ \frac{7\sqrt{2}}{2}\qquad
(C)\ \frac{5 \plus{} 4\sqrt{2}}{2}\qquad
(D)\ \frac{4 \plus{} 5\sqrt{2}}{2}\qquad
(E)\ 7
geometry
Mean of Conditional 5-Digit Numbers
Source:
1/14/2009
What is the average (mean) of all -digit numbers that can be formed by using each of the digits , , , , and exactly once?