A regular dodecagon \(P_1 P_2 P_3 \dotsb P_{12} \)s 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 \(1 \le i < j \le 12\).)

The answer is not,

432, 42, 320, or 252

please help!!!

Guest Jun 17, 2020

#1**+2 **

**A regular dodecahedron \(P_1 P_2 P_3 \dotsb P_{12}\) 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 \(1 \le i < j \le 12\).**

My answer see: https://web2.0calc.com/questions/plshelp#r7

heureka Jun 19, 2020