Triangle Side Analysis: Determining if X+1 Creates a Scalene Triangle

Question

Given the values of the sides of a triangle, is it a triangle with different sides?

XXXAAABBBCCCX+1X+1

Video Solution

Solution Steps

00:00 Determine whether the triangle is scalene
00:03 According to the given side lengths, the triangle is isosceles
00:07 This is the solution

Step-by-Step Solution

To determine if the triangle with sides XX, X+1X+1, X+1X+1 is a scalene triangle, we need to confirm that all sides are of different lengths.

Using the triangle inequality theorem:

  • X+(X+1)>(X+1)2X+1>X+1 X + (X + 1) > (X + 1) \rightarrow 2X + 1 > X + 1, which simplifies to X>0X > 0.
  • X+(X+1)>(X+1)2X+1>X+1 X + (X + 1) > (X + 1) \rightarrow 2X + 1 > X + 1, which also simplifies to X>0X > 0.
  • (X+1)+(X+1)>X2X+2>X (X + 1) + (X + 1) > X \rightarrow 2X + 2 > X, which simplifies to X>2X > -2.

All these conditions are satisfied if XX is a positive number. Next, check if all sides differ:

  • XX and X+1X+1 are different, by definition.
  • However, the two longer sides are both X+1X+1, meaning not all sides are different.

The triangle is thus not scalene, as it does not have all sides of different lengths.

Therefore, the correct answer is No.

Answer

No