Answer:
72
Step-by-step explanation:
Angles of triangles add up to 180
x=180-57-51
x=72
65 degrees
it is 65 because of the vector relationship: 30 + 100 = 130. 130/2=65 degrees
a cause their really isnt any ADEF like in letters
30
because if x is 5 then 6(5)
and 6x5=30
b) 29π mm²