Determine whether the side lengths could represent a right triangle.

14, 21, 25

No

Step-by-step explanation:

Using the given values, 25 is the largest value, so if this were a right triangle, it would be the hypotenuse.

Using Pythagoras' theorem: For this triangle to be a right triangle, √(21² + 14²) must be equal to 25.

√(21² + 14²) = 25.239 (5sf) ≠ 25

Hence the triangle formed is not right.

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.

linear pair postulates