Медиана ad треугольника abc продолжена за сторону bc на отрезок de, равны ad, и точки e соединена с точкой c. а)докажите, что треугольникabc равен треугольникуecd, б)найдите уголace , если угол acd=56 градусам, уголabd=40 градусам

соедени е с в и получишь паралеллограмм авес.

находим угол вас = 180 - 56 - 40 =74 градуса

из свойства паралеллограмма получаем, что угол асе=180 - 74 =106градусов

ответ: 106 градусов

мне ажется так

1.danced, opened, took , rained, had , washed, did ,watched ,cleaned ,went, made , was , got ,lived , wrote

2.we didn't go to Moscow last summer.

the children didn't have dinner at 2o'clock yesterday.

they didn't watch film last week/

I didn't get up at 8 o'clock yesterday.

it didn't rain two days ago

Ann didn't live in S.Petersburg last year/

She didn't read an untersting book the day before  yesterday.

I didn't my homework after school yesterday.

3.where  the children play in the garden yesterday?

did Tom write a latter three days ago&

What father cook dinneh yesterday&

Who mother go  to work by bus yesterday?

When we have a bath the day before yesterday?

Why Nick come home in the aafternoon?

What grandmother make tea in the morning?

4.1 We didn't have lunch at 1o'clock yesterday.Did we have lunch at 1o'clock yesterday? where we have lunch at 1 o'clock  yesterday? Who have lunch at 1 o'clock yesterday?

4.2 It didn't show last week.Did it show last week? Where it show last week? Who ishow last week?

5/1 I halped the mom yesterday.

5/2 where you live last month?

5/3 Did they wake up at 7 am ?

5/4 We didn't go to school yesterday

5/5Who watch the TV on Sunday ?

 

Пусть   меньшая скорость  поезда (из в)   х км/ч, тогда большая  скорость поезда (из а) будет  (х+30) км/ч.  найдём скорость сближения поездов: 300: 2= 150 км/ч, составим уравнение: х+  (х+30)=150 2х=150-30 2х=120 х=60 -скорость одного поезда, тогда 60+30=90 км/ч-скорость второго поезда. 60*2=120 км -расстояние до разъезда от одного поезда( от станции в) 90*2=180 км расстояние до разъезда от другого поезда (от станции а) ответ разъезд находится на расстоянии 180 км от а и 120 км от в.