Биссектрисы углов A и D прямоугольника ABCD делит сторону BC три части Так что длина средней части на 5 см больше крайней Найдите площадь прямоугольника если длина стороны AB равна 4 см

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​

20см

Объяснение:

1) Стороны (отрезки) обычно обозначаются большими буквами: АС, AD и угол ACD,

а маленькими буквами обозначают, например, прямая а, прямая b и т. д.

2) выч (И) сления = чИсла

ABCD - прямоугольник

АС - его диагональ

Треугольник ACD:

AC = 12 см

AD = 10 см

L ADC = 90 град.

L ACD = 60 град.

=>

L CAD = 180 - (L ADC + L ACD) = 180 - (90 + 60) = 30 град.

Против угла в 30 град. лежит сторона = 1\2 гипотенузы =>

CD = 1\2 * AC = 1\2 * 12 = 6 см - вторая сторона прямоугольника

(хотя если решать по теореме Пифагора, то

CD^2 = AC^2 - AD^2 = 12^2 - 10^2 = 144 - 100 = 44 = 6,63 cм,

но это неточность составителя этой задачи, то есть треугольника с АС = 12, AD = 10 и углом ACD в 60 град. быть не может).

Но раз в условии дан угол, будем считать, что CD = 6 cм.

S (ABCD) = AD * CD = 10 * 6 = 60 см^2 - площадь ABCD

P (ABCD) = 2 * (AD + CD) = 2 * (10 + 6) = 32 см - периметр ABCD