A square has sides of length 8.4 . Work out the length of a diagnol of the square . Give your answer correct to 3 significant figures

The length of the diagonal is 11.879 units

Step-by-step explanation:

On any rectangle or square, any 2 adjacent sides and the diagonal that connects them makes a right triangle. The diagonal is the hypotenuse of that right triangle, and you can find it using the pythagorean theorem:

where a and b are the sides, and c is the diagonal.

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.

step-by-step :