The absolute value of -5 is 5, and the absolute value of 5 is also 5. ∣ a + b i ∣ = a 2 + b 2 . |a+bi| = \sqrt{a^2 +b^2}.
The second choice for the first problem and the third choice for the second problem
If u think of it this way
8*4=32 it has to be smaller than that so my best guess would be
C) 20 square units
Firstly, find the radius with the formula diameter (d) : 2
8 : 2 = 4 cm
The Vilume formula is r²hπ = 4²*12*π = 16*12*π = 192π cm³
Your exercise says to use "3" as a value for π
Then V is 192*3 = 576 cm³