Question

У треугольника ABC угол B=90градусов; AB=3см;BC=4см. Найти Cos угла А.

Answer 1

COS A=3/4=0,75  это отношение катета прилещашего к гипотенузе

Answer 2

Finding the Cosine of Angle A in Triangle ABC

Given: - Angle B = 90 degrees - AB = 3 cm - BC = 4 cm

To find: Cosine of angle A

Solution

Using the Pythagorean theorem, we can find the length of AC: - AC = √(AB^2 + BC^2) - AC = √(3^2 + 4^2) - AC = √(9 + 16) - AC = √25 - AC = 5 cm

Now, we can find the cosine of angle A using the formula: - Cosine of angle A = Adjacent side / Hypotenuse - Cosine A = AB / AC - Cosine A = 3 / 5 - Cosine A = 0.6

Therefore, the cosine of angle A in triangle ABC is 0.6.