Question

1. What is the area of a square of a side 21 cm?

2. A square of perimeter 16 cm has an area of __ cm?
3. A rectangle of perimeter is 100 cm and width 20 cm, as a length of __ cm?
4. A square is equal to a rectangle in an area. If the length of a rectangle is 18 and its width is 8, what is the perimeter of the square?
5. What is the area of a circle with radius 9 cm?

Answer 1

Explanation:

1) to calculate the area of ​​a square you must do: side x side so 21 x 21 = 441

2) The perimeter is calculated by: side x 4

So to find the length of a side, you divide 16 by 4.

Next, you have to calculate the area of ​​this square with a side of 16 cm.

You just have to do 16 x 16

3) The formula to calculate the perimeter of a rectangle is: Length x Width

So you divide 100 by 20 and you get the length of your rectangle

Answer 2

Explanation:

1) 21 x 21 = 441cm²

2) 16/4=4 4 x 4 = 16cm²

3) 100-40 = 60/2 = 30cm

4)18 x 8 = 144cm/2=72 72x 4=288cm

5) π x 9²=81πcm²