<prompt> Mraba ABCD ina urefu wa upande 13, na pointi E na F ziko nje ya mraba kama vile BEDF5 na AECF12. Tafuta EF2.asyunitsize0.2 cm; jozi A, B, C, D, E, F; A 0,13; B 13,13; C 13,0; D 0,0; E A 121213,51213; F D 5513,-51213; kuchoraA--B--C--D--mzunguko; choraA--E--B; kuchoraC--F--D; nukta A, A, W; nuktaB, B, dir0; nuktaC, C, dir0; nukta D, D, W; nukta E, E, N; nuktaF, F, S;asy  <response>: Acha angle FCD alpha, ili FB sqrt122 132 2cdot12cdot13sinalpha sqrt433. Kwa ulalo, DB 13sqrt2, DB2 338.Jumla ya miraba ya pande za parallelogramu ni jumla ya miraba ya diagonals.EF2 2cdot52 433 - 338 578. 