605 pounds is 840.25 dollars
405 dollars is 313.30 pounds
The answer is 80! If you ever see any angle like that where it’s just two lines (I don’t know how to explain it/forgot what it’s called) it will be the same as the other angle.
If the perimeter is 28 units, then you know you will have to add the same four numbers to get the perimeter. What times 4 can get you to 28? 7. 7 x 4=28. So what plus 3 gets us to 7? 4. The answer is 4, or x=4.
The mean is all of them added together divided by the number, so multiple the mean by the number of sides, 3, and that's the perimeter. 18 x 3 = 54
