Answer:
90
Step-by-step explanation:
a triangle's angles all add up to 180. take 51 and 39 away from 180 and you get 90
Answer:
4000 gallons.
Step-by-step explanation:
One day's discharge at the mouth of the river is 2 trillion gallons and it can supply all of country A's households for five months.
Now, if there are 100 million households in country A.
Then, the amount of water an average household uses each month will be given by
gallons. (Answer)
A=bh
A=471.5(21.3)=10042.95cm2