GMAT MATH - Geometry
April 26, 2004
What is the measure of the circum radius of a triangle whose sides are 9, 40 and 41?
| (A) | 6 |
| (B) | 4 |
| (C) | 24.5 |
| (D) | 20.5 |
| (E) | 12.5 |
Correct Choice (D) Answer (20.5)
Explanatory Answer
From the measure of the length of the sides of the triangle, 9, 40 and 41 we can infer that the triangle is a right angled triangled. 9-40-41 is a Pythagorean triplet.
In a right angled triangle, the circum radius is half the hypotenuse.
In the given triangle, the hypotenuse = 41.
Therefore, the circum radius =  = 20.5 units.
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