At my young man's birthday and he wanted to get compliments from a dj, there the possibility of writing in dj tweeter he can fulfill this wish, but the fact that he knows very little Russian, mostly spoke in English). Here is the text. Hello, my young man's birthday soon, 18 years old, he is very fond of your tracks and listen to them for six years. Went on AfP to your concert, he scored the entire phone videos to your presentation, you are his favorite dj, he really wants you to congratulated him, you could not write a greeting and take pictures?)
АВ = AM + MN + NB; АМ + NB = AB – MN = 28 см – 16 см = 12 см. М – середина АС, значит, АМ = MС;
N – середина BD, значит, BN = ND.
Так как АМ + NB = 12 см, АМ = МС, BN = ND, то MC + DN = 12 см. MN = МС + CD + DN = 16 см,
МС + DN = 12 см, значит, CD = MN – (MC + DN) = 16 см – 12 см = 4 см.
ответ: 4 см