The percentage of rain fall in the dry desserts is less than 10%
No, this is false although it's not very far from it!
Etymology means the study of the meaning of the word, and especially the way this meaning has changed over time. So the fact that a word has a German origin (for example Bratwurst) would be the etymology of this word
Your statement is false, the sun's most direct rays would be striking the Tropic of Capricorn which is located at 23.5 degrees south in latitude, in the southern hemisphere. When the earth is tilted this way, the north pole is rotated further away from the sun that the south pole is.