for a normal triangle its (bh)/2 but this is a right triangle so you multiply the two perpendicular sides and divide it by 2
Answer:
8
Step-by-step explanation:

The answer is .015
Hope this helps
Practice proportionality. A 50 difference between 100 and 150 is less relevant than 50 in 25 and 75. Its like you have 1 billion dollars and i give you 10 dollars. Its worthless right? What if you have 20 dollars and i give you again 10 dollars, its half of what you have. See the difference? Same number but different value.
Set 4 is the correct answer because if you multiply 10 by 10 + 20 times 20, you will get 400 and when you multiply 30 by 30 you also get 400 which is equal to 400 there for you answer would be set 4.
Hope I helped if I did click the thx button ;)