Question

A rectangle is divided into 15 identical squares arranged in three rows. What is the perimeter of the rectangle, in centimeters, if the area of one little square is 9 cm2? (A) 24 (B) 48 (C) 60 (D) 75 (E) 105

Answer 1

48 cm

Explanation:

Here, we are concerned with finding the perimeter of the rectangle.

Now, since the square has an area of 9 cm^2, it means that the squares has a side of 3 cm each since the area of a square is s^2

So now, there are 5 squares in a row, meaning in a straight stretch , left to right or right to left, there are 15 squares. So the total length here is 5 * 3 = 15 cm

Now, moving column-wise, from top to bottom, since we have 3 rows, what this means is that per column of the rows, there are 3 squares. So the total length here becomes 3 * 3 = 9 cm

So we have a rectangle 9cm by 15cm

The perimeter is thus 2(L + B) = 2(15 + 9) = 2(24) = 48 cm