Question

СРОЧНО НУЖЕН ОТВЕТ A (1;0) B (1;2) C (-3;-2) кут B - ?

Answer 1

Кут B - 4 ; + 3 ет точно

Answer 2

To find the angle at B, we can use the Law of Cosines, which states that for a triangle with sides of length a, b, and c opposite to angles A, B, and C, respectively,

c^2 = a^2 + b^2 - 2ab*cos(C)

In this case, we want to find the angle at B, so we'll use sides AB and BC:

AB = sqrt((1-1)^2 + (2-0)^2) = sqrt(4) = 2 BC = sqrt((-3-1)^2 + (-2-2)^2) = sqrt(40) = 2*sqrt(10)

We also know that angle B is opposite to side AB, so we can label it as angle A. Similarly, angle C is opposite to side BC.

Now we can use the Law of Cosines:

(2sqrt(10))^2 = 2^2 + (2sqrt(10))^2 - 22(2)*cos(A)

Simplifying:

40 = 4 + 40 - 8*cos(A)

8*cos(A) = 4

cos(A) = 1/2

A = 60 degrees (since cos(60) = 1/2)

Therefore, angle B is 180 - A - C:

B = 180 - 60 - arctan((2+2)/(1-(-3))) B = 180 - 60 - arctan(4/4) B = 120 - 45 B = 75 degrees

So the answer is 75 degrees.