The first one is the best answer
2.7 would be 2 7/10. Correct?
Only the third one makes x=-1 true
Volume = area of base *height
20 = pir^2 *h
20 = 3,14*4*h
h = 20/12,56 = 1,59 rounded 1,6
- using the triangle formed by radius,the height of cup and the slant height of cup so we can writing that
tan ß = h/r so tan ß = 1,6/2 = 0,8
tan ß = 0,8 so ß = arctan 0,8 = 38,6 degrees so 39 degrees
hope helped
You can pick a symbol, maybe m or z to be the symbol.