4. площадь данного треугольника равна 180 см. его ортогональной проекцией на
некоторую плоскость является треугольник со сторонами 12 см, 17 см и 25 см. чему
равен угол между плоскостями этих треугольников? с чертежом​

Fast food is harmful because of it fat. And that boys, especially for girls is very bad. Fast food - the culprit of many diseases. Contains murderous for gastrointestinal food. in any case not be accustomed to the fast food for their children. It is terrible to see how families with children aged 3-5 years are marching toward the McDonald's on the "family fast food." Among other things, the abuse of fast food at such a tender age can lead to delays in the development, disorders of the nervous system of the child, weakening of the immune system.

- Hi, my friend. 
- Good morning. 
- Yesterday, I was thinking a lot and finally decided I need to do sports.
- Perfect, and is it possible also for me to do it with you? 
- Yes, of course. What sport activities are the most pleasent to you?
- I wanted to be engaged in snowboarding long ago. Recently I bought a board.
- Perfectly, you don't know how much is to enter a sports community?
- Sorry, but not yet. 
- To what mountain will we go first?
- On Uktus.
- Then, we will go there two times a week.
- That's settled then.