Respuesta :

The lengths of the third side must be greater than 10 , but less than 30.

What is triangle inequality theorem?

This theorem states that the sum of any two sides of a triangle must be greater than the third side.

The given two sides of triangle is 10 and 20.

Let x be the third side of the triangle.

Now the sum of the given two sides

10 + 20 = 30

Now,according to triangle inequality theorem

x < sum of other two sides

⇒ x < 30

Now Since two sides are 10 and 20 and third side is x.

and we know that x < 30

Let third side be the smallest side.

then x ≤ 10

⇒ x + 10 > 20

⇒ x > 10.

Hence,The lengths of the third side must be greater than 10, but less than 30.

More about triangle inequality theorem :

https://brainly.com/question/1820178

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