Question

Look at the napkin holder.

A napkin holder with two identical triangular sides.

Which could be the lengths of the triangular sides of the napkin holder?

4 cm, 10 cm, 5 cm

6 cm, 12 cm, 5 cm

5 cm, 3 cm, 9 cm

7 cm, 5 cm, 6 cm

Answer 1

In a triangle, the sum of the lengths of any two sides must be greater than the length of the third side.

Answer 2

For each choice, take the sides, 2 at a time. If their sum is greater than the other side, then it's a psossible triangle. For each choice, you need to do 3 different sums.

Answer 3

So A or C?

Answer 4

Let's do A together.
Sides: 4 cm, 10 cm, 5 cm

Side 1 + Side 2: 4 + 10 = 14, 14 > 5 ---> good

Side 2 + Side 3: 10 + 5 = 15, 15 > 10 ---> good

Side 1 + Side 3: 4 + 5 = 9, 9 < 10 -------> no good

Choice A will not gives us a triangle.
If any of the comparisons is no good, there is no triangle.

Answer 5

This is what you need to do with each choice.