Question

I do not know this answer

Answer 1

Answer: 15

Explanation:

Let's start by stating what we are given

The perimeter is 36

One side length is 12

And the other given side is 9

Finally we have an unknown side x

The value of all the sides added together is the perimeter.

So add all the sides

12+9+x=36

21+x=36

Subtract both sides by 21

21-21+x=36-21

x=15

Answer 2

15 miles

Use the Pythagoras theorem