Zero.
Anything times zero is zero.
-20 * -10 = 200
200 * -1 = -200
-200 * 0 = 0
Area of one blade is
A=(1/2)b*h=(1/2)7*4=28/2=14
for four blades
14*4=56
Answer:
C
Step-by-step explanation:
If you look on jiskha you will find the answer you will be looking for just type it in B
