Find the angle A of a right-angled triangle ABC if the side CA = 7, BC = 7√3.

By definition, the tangent in a right-angled triangle is the ratio of the opposite leg to the adjacent leg, we get that:

tg A = BC / CA.

We know from the condition that:

BC = 7√3;

CA = 7.

Thus, we get that:

tg A = BC / CA = 7√3: 7 = (7√3) / 7 = √3.

Thus, we get that the angle A = 60 °.

Answer: A = 60 °.

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