In triangle ABC AC = 4, BC = 3, angle C = 90 degrees. Find the radius of the circumscribed circle of this triangle.

1. By the condition of the problem ∠С = 90 °. Hence the given triangle is rectangular.

2. Calculate the length AB – the hypotenuse of a given right-angled triangle. To perform the calculation, we use the Pythagorean theorem:

AB = √BC² + AC² = √3² + 4² = √9 + 16 = √25 = 5 units.

3. Calculate the radius of the circle (R), which is described around a given triangle:

R = AB: 2 = 5: 2 = 2.5 units.

Answer: The radius of the circle that is described by the given triangle is 2.5 units.