You build a box that is 4 feet long, 5 feet wide, and 8 feet high. The distance from the top left front corner to the top right back corner is ______.

I tried
a²= 4² + 5²
a²= 41

d² = 41 + 8²
d²= 105
d=+- 10.25

is this right?

1 answer

d^2=4^2+5^2+8^2=16+25+64=105
d= sqrt 105

Now, your answer, notice I did not put -. How can a measurement on a box be negative?