The answer is D. The bottom number is multiplied by two each time.
1. 4^2 +x^2 = 6^2
16 + x^2 = 36
x^2 = 20, x = sqrt(20) = 4.47 miles
2. using the same equation as above: 20 inches
3. needs to be a right triangle so A
4. using distance formula answer is 7.07 units
5.volume cylinder: 62.82, volume sphere: 33.51, difference:=62.82 -33.51 = 29.31 cubic inches
D:
The orthocenter will be inside, on, or outside the scalene triangle, depending on whether it is acute, right, or obtuse, respectively. The number of congruent sides does not affect the location of the orthocenter.