точка м пренадлежит отрезку аб.наидите расстояние между серединами отрезков ам и мб,аб=6 см

Нужен реферат на тему история создания и развития термометра

1)Peter seldom (tell) the truth/ You can't believe everything he (say)

2)You (understand) what he (talk) about? 

3) What you (do)? - I'm an accountant. 

4)The steak (taste) good, doesn't it? 

5)Your brother (be) a student now? - es, he (study) at university.

9)The steak (taste)good, does not  it?

10)Your brother be)a student now?- Yes, he study)at  university.

11)Ann (play)the piano  better than Susan. And  who play) now?-I (think) it (be)   Susan.

 12) Stop disturbing me! Can't you see I (work)?

13) (Be) this information up-to-date? (Include) it the most recent changes?

30) You (believe) in God? 

32) You alwAYS (COMPLAIN) ABOUT THE WEATHER! 

Прямые КА, КВ и КС попарно перпендикулярны.Найдите отрезок ВС, если КА=3 см, АВ=7 см, КС= 1,5 см