The answer would be 6 because 20-4=16. So to make it equal to that 6+4=10. Since it is not you need 6 more so answer is 6.
Answer:
45
Step-by-step explanation:
Set up ratios for 2 similar triangles:
20/28=x/x+18
Cross multiply
28x=20x+360
8x=360
x=45
A = 45
b = 75
c = 37
d = 137
a-
whenever the angle is shaped like that they are equal i forgot the actual property name though
b-
and the known angles up (so 45 and 60) then subtract 105 from 180 to get 75 which is the answer
c-
add the known angles then subtract from 180 (so add 75 and 68) then u should get 37
d-
add all known angles then subtract from 180 (so add 37 and 100) you should get 43
then ur gonna subtract 43 from 180 to get the answer which is 137