50 POINTS !! PLEASE HELP
EXPLAIN HOW YOU GOT IT

ILL GIVE BRAINLIEST TO THE RIGHT ANSWERS.

35

Step-by-step explanation:

So, lets go over what we know.

One side length is 28.

The other side length is 21.

The missing hypotenuse(longest length) is x.

We can use the pythagreons theorm to find x:

A^2+B^2=C^2. Remember that the two smaller side lengths are A and B, while the longest side length(in this case x) is C.

Plugging in our values:

28^2+21^2=x^2

Distrubute the ^2:

784+441=x^2

Combine the two side lengths:

1225=x^2

Now square root both sides to get x^2 alone(as x)

35=x

So our missing side length, x, is 35!

Hope this helps! :D