Can someone me with these two questions, because i really don't understand them.

~Hello There!~

19. You can use Pythagoras to figure out the missing length of the triangle
√15² - 9² = 12
(12 x 9)/2 = 54
((20 + 32) / 2) x 9 = 234
234 + 54 = 288

That's what i got ^^ Not 100% sure if its correct

20. 8 + 3 + 6 + 3 = 20
20/4 = 5
Mean = 5

Hope This Helps You!
Good Luck :)
Have A Great Day ^_^

- Hannah ❤

The answer is