What was one contribution made by eratosthenes in ancient greece

a. he wrote a geometry textbook that was used for nearly 2,000 years

b. he calculated the value of the infinite number known as pi

c. he computed the circumference of planet earth

d. he developed military tactics that still apply today

Born in Cyrene around the year 276 BC, Eratosthenes was an Ancient Greek mathematician and thinker, he even was the leader for some time of the famous Library of Alexandria. He is attributed to have invented geography.  

In one of Eratosthenes' most famous experiments, he compared the altitudes of the sun in the sky, in two different locations, one in a northern land and the other one in the south.  With these two altitudes, he was able to mathematically calculate with an impressive presition the circumference of the Earth, for this, and other important achievements, some historians state he was way ahead of his time.

So the correct answer is C.) He computed the circumference of planet earth

(C)-He computed the circumference of planet Earth.

Explanation:

I just know :)

all of the following apply except for (a. excessive credit on real estate resulting in defaulted loans.

in 1819, panic swept the country due,in part, to the rapid expansion of american manufacturing during the war of 1812 and the distress caused by the post-war british competition. the rapid expansion of american farming was another factor.

explanation:

1. ford: gerald ford´s presidency, from 1974 to 1977, faced high inflation, named it public enemy nº1, and created the win program (whip inflation now).

2. carter: president from 1977 to 1981, carter had controversial poitions over abortion, but yet, he enforce the roe vs wade decision, which had pro-choice content.

3. reagan. for his eloquency and powerful speeches in his mandates, from 1981 to 1989, reagan earned this nickname, “the great communicator” .

4. george h w bush: despite many presidents had important roles in managing and trying to end the cold war, it was in bush sr's mandate that the berlin wall was materially destroyed, and he was visited by gorbachev in the uspresident from 1989 to 1993.

5. clinton: defense of marriage act. clinton signed this controvesial act, which defined marriage and spouses in strict heterosexual perspective, that was later declard unconstitutional by the us supreme court.

6. george w bush: in the begining of his presidency, which lasted until 2009, bush jr faced the greatest terrorist attacks in us and probably the worlds history, in september, 11 of 2001.

7. obama: in attempts to cease a great economical crisis, barack obama signed the controversial recovery act in february 2009, which handled 780-billion dollars.