Answer:
The Answer is 81.7 [Rounded] Exact is 81.6714
Step-by-step explanation: First, You would divide diameter by 2 for the radius to answer the area which is 5.1 then do it to the second power 5.1 x 5.1 which equals to 26.01 then multiply it by 3.14 to get your answer which is 81.6714 and its 81.67 unless your required to round and if its a semi circle instead multiply 26.01 x 1.57(half of pie) that equals to 40.83 rounded and the exact is 40.8357. - The End A Middle School 7th Grade :)