Впараллелограмме abcd биссектриса острого угла c пересекает сторону ad в точке m, а продолжение стороны ab в точке k, km : mc = 2: 3. найдите стороны параллелограмма abcd, если его периметр равен 48 см.

треугольники амк и дмс подобны по двум углам. отсюда следует, что ам/мд=2/3.треугольник сдм- равнобедренный(т.к см- биссектриса).значит мд=сд. пусть х- одна часть, тогда ад=5х,сд=3х

  p(abcd)=2*(ab+cd)

2*(3x+5x)=48 

  16x=48

  x=48/16

  x=3

  3x=9

  5x=15 ответ 9,15

1 My father's mother is my grandmother

 2 my uncle's son is my cousin

 3 my mom's sister my aunt

 4 sister of my son my daughter

 5 my cousin father my uncle

 6 my parent's daughter my sister

 7 my grandmother's husband my grandfather

 8 my brother my grandmother grandson

1 Мать моего отца - моя бабушка

2 сын моего дяди мой двоюродный

3 сестра моей мамы моя тетя

4 сестра моего сына моя дочь

5 отец моего двоюродного брата мой дядя

6 дочь моего родителя моя сестра

7 муж моей бабушки мой дедушка

8 мой брат моей бабушке внук

Объяснение:

Progress Cheek 1 I variant 1.Complete the sentences in past perfect 1. When I came home, mother already (to cook) dinner. 2. When father returned from work, we already (to do) our homework. 3. When the teacher entered the classroom, the pupils already (10 open) their books. 4. Kate gave me the book which she (to buy) the day before 5. Nick showed the teacher the picture which he (to draw). 6. The boy gave the goats the grass which he (to bring) from the ficld 2. Write the sentences in the interrogative form and make general and who-questions. 1. Rose had written the letter by 7 о'clock yesterday. 2 Mrs Rogers had cooked the dinner by 6 о'clock last Sunday. 3. Jane and Ann had built the toy house by four o'clock yesterday. 3. Choose the right words to complete the sentences. 1) That day Jane felt so sad ahe could (ery/smile). 2) The puplls (ended/ finished) decorating the hall late in the afternoon. 3) Do you watch matehes of your favourite football (сrеw/teаm) on television? 4) We are playing basketball in the gyт, would you 1ike to joln (- /1in)? 5) No one liked the dish, we thought it was rather (Lasteful/tasteless). 6) In the I variant 1.Compleie the sentences in past рerfect b) hie