+0

# Pls help

0
81
1

A regular dodecagon \$P_1 P_2 P_3 \dotsb P_{12}\$ is inscribed in a circle with radius \$1.\$ Compute
\[(P_1 P_2)^2 + (P_1 P_3)^2 + \dots + (P_{11} P_{12})^2.\](The sum includes all terms of the form \$(P_i P_j)^2,\$ where \$1 \le i < j \le 12.\$)

Mar 22, 2020
edited by Guest  Mar 22, 2020