<em>Чертеж во вложении. </em>
1) Проведем высоты ВВ1 и СС1. Получим квадрат (ВС=ВВ1 по усл), В1С1=12 см.
2) Рассмотрим ΔАВВ1: он прямоугольный, угол А = 45° (по усл), значит ВВ1=АВ1=12 см.
3) ΔАВВ1=ΔСС1D (по гипотенузе и острому углу: угол A= углу D по условию, АВ=CD тр-я равнобедр). ⇒AB1=C1D=12см
4) AD=AB1+B1C+C1D=3*12см=36 см.
5) Sabcd= 1/2*ВВ1*(ВС+AD)=1/2*12*(12+36)=6см*48см=288 см^2
Ответ: 228 cм^2.
Угол с=90, тогда проекция АС на АВ, равна половине гипотенузы, т.е. 9,5
Дуга в 2 раза больше угла на которую он опирается. Одна дуга = 60*2=120, вторая = 80*2=190, третья = 360-120-180=100. Буквы сама поставишь какие захочешь)
This autumn my mother, sister and me traveled to Spain. It took us much time to get to Spain, but it was worth it. I was very surprised to find out that the weather in Spain is hot, because in Russia it was too cold. Many people in Spain do not speak Russian, many people wear very simple clothes, and it was difficult to get used to.
There we met many children. We did not notice that they did not understand us. We were friends and played together. My family and I often walked along the streets. It was wonderful. Streets in Spain are very clean. We also visited a large aquarium. There we saw different fishes, sharks, and rays. We spent two weeks in Spain.
When we came back to Russia it was already snowing here. I enjoyed the trip.
