Shapes within shapes

12 questions

1. 25% of 2640 is ___.
2. 20 as a percentage of 50 is ___%
3. The area of a square with edge lengths of 1.4 cm is ___ cm².
4. The area of a circle with a diameter of 30 m is ___\pi m².
5. Here are the first seven triangular numbers: 1, 3, 6, 10, 15, 21, 28. The next triangular number is ___.
6. The numbers 1, 4, 9, 16, 25, 36, 49, ... are called the ___ numbers.
7. A shape has a total area of 50 cm². Part of the shape is shaded. An area of 24 cm² is left unshaded. ___% of the shape is shaded.
8. A shape has a total area of 45 cm². Part of the shape is shaded. An area of 27 cm² is left unshaded. ___% of the shape is shaded.
9. Which descriptors of this shape are correct?
10. The percentage of the shape which is shaded is ___%.
11. Which calculation is correct to find the percentage of the rectilinear compound shape which is shaded?
12. This shape is made from a circle and the removal of two congruent circles. The percentage shaded in this shape is ___%.

License: OGL