B) Side length of B to side length of C is 4:5.
Perimeter of C is 280, so let's put that into the side length of C's place:
4:280
But the 4 also would have to change so let's figure out how much we multiplied 5 by to get 280:
280 / 5 = 56
So let's do 4 x 56 = 224
Our new ratio is 224:280
Therefore the perimeter of mirror B is 224cm.
C) Side length of A to side length of B is 3:4.
We know the perimeter of B from the previous part (224) so let's put that in the 4s place:
3:224
But we also have to change 3, so let's figure out how much we multiplied 4 by to get 224:
224 / 4 = 56
Therefore to determine A's perimeter we do 3 x 56 = 168.
Mirror A's perimeter is 168cm.
D) The side length of mirror A is the perimeter divided by 4 (as they are squares).
168 / 4 = 42. Side length of mirror A is 42cm.
E) Area of a square is side length squared, so the area of mirror A is 42².
42² = 1,764cm².
