Középiskolai Matematikai és Fizikai Lapok
Informatika rovattal
 [6] Peter Erben 2022-01-14 11:20:32 The motivation for the previous solution was a property of the diagonals of a regular 18-gon: their angle is always a multiple of $\displaystyle 10 ^\circ$. Also, we can choose three of these diagonals in many ways so that the three chosen diagonals are concurrent. Előzmény: [5] Peter Erben, 2022-01-14 11:08:41
 [5] Peter Erben 2022-01-14 11:08:41 Nice solution. Another approach could be to draw a $\displaystyle BCG$ equilateral triangle and prove by contradiction that $\displaystyle G$ should line on the segment $\displaystyle AD$. Előzmény: [4] Lpont, 2022-01-13 22:53:04
 [1] perash 2022-01-11 21:22:59 Given a convex quadrilateral $\displaystyle ABCD$ with $\displaystyle AB = BC = CD$ and $\displaystyle m(\angle DAB) = {7x }$,$\displaystyle \,m(\angle A BC) = {10x }$, $\displaystyle m(\angle CDA) = { 5x }$, Find $\displaystyle m(\angle BCD)$.