Which of the following sets of possible side lengths forms a triangle? 6, 9, and 15 4, 10, and 15 10, 15, and 25 12, 12, and 23

 12, 12, and 23

Step-by-step explanation:

By definition, when three lengths form a triangle, the sum of two of them must be greater that the third lenght.

To find out which of the options given in the problem form a triangle, you must add the first two lenghts and verify that the sum is greater than the third lenght.

Keeping this on mind, when you verify the last option you have:

12+12=24

24>23

Therefore, the answer is the last option.

step-by-step explanation:

use pothagarean therom

a^2+b^2=c^2 so first ac

acm is a right triangle because c= 90°

and am (the hypotenuse or c) =16+9 =25

but there is not enough info we need another angle or side length

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.