Triangle Side Measurements: Is 25-28-28 a Scalene Triangle?

The problem requires us to determine if the triangle with given side lengths is a scalene triangle, which means all sides must be different.

We start by verifying if these side lengths form a triangle using the triangle inequality theorem, which states for any triangle with sides $a$, $b$, and $c$:

• $a + b > c$
• $a + c > b$
• $b + c > a$

Denote the given side lengths as follows:
$a = 28$, $b = 28$, $c = 25$.

Check the triangle inequalities:
$28 + 28 = 56$ which is indeed greater than $25$.
$28 + 25 = 53$ which is greater than $28$.
$25 + 28 = 53$ which is again greater than $28$.

Since all inequalities hold, these sides indeed form a triangle.

Next, determine if it is a scalene triangle. A scalene triangle has all sides of different lengths.

In our case, $a = 28 = b$, and $c = 25$. The sides $a$ and $b$ are not distinct, hence the triangle is not scalene but isosceles.

Therefore, the triangle does not have all different sides.

Thus, the correct answer is: No.