Answer:
Step-by-step explanation:
External angle equals to the sum of opposite internal angles
z - 41° + z - 20° = z + 40°
2z - 61° = z + 40°
2z - z - 61° = 40°
z - 61° = 40
z = 40° + 61°
z = 101°
thats the answer just look at the picture :)
for the work
Total bill-$67.95
each friends owes about $16.99
The answer to your question is 18, how 20\100x90=18