Question

56. Which of the following sets of measurementscould NOT represent the lengths of the threesides that would form a triangle?A. 3 ft, 4 ft, 5 ft.B. 5 cm, 8 cm, 15 cmC. 7 in, 7 in, 7 inD. 10 m, 10 m, 15 m

Answer 1

B

Explanation:

We know that in a triangle, the sum of any two sides must be greater than the third side, so all we need to do is to calculate the sum of the two sides. There is a tip, you only need to see if the sum of two shorter sides of the triangle is bigger than the third side, if it is, then it is a triangle. (No need to add 3 times!!!)

1. A, 3+4=7, and 7>5, the sum of two shorter sides is bigger than the longest side, so this can be a triangle.

2. B, 5+8=13, and 13<15, the sum of two shorter sides is smaller than the longest side, so this cannot be a triangle.

3. C, all of them are equal, so the sum of two sides will certainly be greater than the third side.

4. D, 10+10=20, and 20>15, the sum of two shorter sides of the triangle is greater than the third side, so this is a triangle.

Hope this will help:)