Нужна геометрия 7 класс

ответ:

с — точка, касания плоскости α со сферой; плоскость с — касательная к сфере; β образует с α угол φ; β пересекается с шаром по окружности, диаметр которой св.

построим оо1 ⊥ св, соединим точку о с точками с и в. δоо1с = δоо1b (прямоугольные, оо1 — общий катет, ос = ов = r). тогда, со1 = о1b, точка о1 — центр окружности,

по которой плоскость β пересекает шар.

построим сечение шара плоскостью сов. φ — угол между плоскостями α и β.

∠ocb = 90o -φ, поскольку δboc — равнобедренный, то ∠obo1 = 90o -φ.

из δоо1b:

площадь сечения шара

объяснение:

Speaking Task 1. Choose the question from the card on the topic Entertainment and fedia^ prime prime and be ready to answer it after the teacher starts the conversation. Produce a speech by giving extended answers to the questions. Share your ideas with the class. Teacher organizes a Socratic seminar, which helps him/her to assess learners while they are speaking on the toplic Entertainment and Media and he/she prepares and cuts down questions and expressions beforehand. Learners sit in a circle and answer the question using in their speech some formal and Informal expressions to present logically connected information to their classmates. Expressions: Stating an opinion The way I see it... Sorry to interrupt, but... Is it okay if I jump in for a second? Can I add something here? Can I throw my two cents in? Not necessarily Interrupting If I might add something..... I beg to differ No, I'm not so sure about that That's for sure Expressing disagreement I'd say the exact opposite I have to side with somebody (name)on this one I was just going to say that In my opinion Expressing agreement If you ask me.. That's exactly how I feel As far as I'm concerned. If you want my honest opinion..... You have a point there That's not always the case​