In 1956, uprisings behind the iron curtain occurred in

  Poland and Hungary

Explanation:

  The Iron Curtain was the physical boundary that divided Europe into two separate areas. From the end of World War II until 1991.

  In 1956 the Hungarian Uprising was a nationwide revolution against the Hungarian People´s Republic and the Soviet-imposed policies. It was the first major threat to the Soviet Union since World War II.

  In Poland, also in 1956, there were a series of protests against the communist government of the Polish People´s Republic. It began with workers demanding better working conditions and were met with violent repression.

  I hope this answer helps you.

254.34

step-by-step explanation:

the formula for area of a circle is given by

a = pi * r^2

a = pi * 9^2

a = 81*pi

using 3.14 as an approximation for pi

a = 3.14*81

a = 254.34