Четырехугольник АВСД, уголАВД=71 =1/2*дугаАД, дугаАД=2*71=142,
уголСАД=61=1/2дугиДС, дуга ДС=2*61=122, ДугаАС=дугаАД+дугаДС=142+122=264
уголАВС=1/2дугиАС=264/2=132
Получается:
Одна сторона: х, х+41, 4х
х+х+41+4х=107
6х=66
х=11
х+41=52
4х=44
Вспоминаем свойство параллелограмма:
<em>Диагонали параллелограмма пересекаются и точкой пересечения делятся пополам</em>
Смотрим на рисунок: половина большой диагонали равна 2,5 см
Малая диагональ, собственно, есть сторона иначального квадрата, её мы обозначаем за а, её половина равна а/2.
Ну и решаем:
см²
Had remembered, would have sent
Hadn't been ill, would have gone
Wouldn't have broken, had been
Would have got, hadn't taken
Had done, Wouldn't have shouted
Would have passed, had studied
Had closed, Wouldn't have run away
Would have lost, hadn't picked
Had saved, he would have been able