MATH

12345678
Across
  1. 4. bh
  2. 5. opposite of subtraction
  3. 6. opposite of addition
  4. 7. radiusx2
  5. 8. all positive and negative numbers
Down
  1. 1. a^2+b^2=c^2
  2. 2. only positive whole numbers
  3. 3. 2rxpi