Perfect squares are n² where n is a whole number
whole numbers are like 0,1,2,3,4,5,6, etc
no decimal or fractions
we can do that be looking at the perfect squares we know
2²=4
3²=9
4²=16
5²=25
6²=36
7²=49
8²=64
etc
so we see 47 is between 6² and 7²
therefor, for n²=47, n is between 6 and 7 and is therfore not a whole number
that makes 47 not a perfect square
C)
Area of full triangle
1/2(8)(6)=24cm^2
Area of non shaded triangle
1/2(4)(3)=6cm^2
Area of full minus area of small triangle
24-6=18cm^2
D)
Area of Big rectangle
(4)(12)=48
Area of non shaded triangle
1/2(9)(4)=18
Area of Big rectangle minus non shaded triangle
48-18=30cm^2
I’m pretty sure the answer is D. Sorry if I’m wrong
