In a triangle ABC AC = BC = 2 AB = 2. Find cosA. In a triangle ABC AC = BC = 13 AB = 10. Find tgA.

one.

Since, by condition, the lengths of all sides of the triangle are equal to 2 cm, then the ABC triangle is equilateral, and all its internal angles are 60.

Then CosA = Cos60 = 1/2.

Answer: The cosine of angle A is 1/2.

2.

Triangle ABC is isosceles with base AB since AC = BC.

Let’s build the height of CH, which is also its median. Then AH = BH = AB / 2 = 5 cm. In a right-angled triangle ACN, according to the Pythagorean theorem, we determine the length of the leg CH.

CH ^ 2 = AC ^ 2 – AH ^ 2 = 169 – 25 = 144. CH = 12 cm.

Then tgA = CH / AB = 12/5 = 2.4.

Answer: The tangent of angle A is 2.4.