Polygons

9000020910

Level: 
A
The perimeter of a rectangle is \(28\, \mathrm{cm}\). The diagonal of this rectangle is \(10\, \mathrm{cm}\). Find the sides of the rectangle.
\(8\, \mathrm{cm}\) and \(6\, \mathrm{cm}\)
\(7\, \mathrm{cm}\) and \(7\, \mathrm{cm}\)
\(9\, \mathrm{cm}\) and \(5\, \mathrm{cm}\)
\(7\, \mathrm{cm}\) and \(3\, \mathrm{cm}\)

1003021308

Level: 
B
Choose the wrong claim:
The sum of the opposite angles in a rectangle is \( 360^{\circ} \).
The sum of the interior angles of a convex n-gon is \( (n-2)\cdot180^{\circ} \).
If there is just one pair of sides parallel in a quadrilateral and the other side is perpendicular to them, then the quadrilateral is a right-angled trapezium.
At least one of the interior angles in a trapezium is obtuse.

1003055006

Level: 
B
A regular pentadecagon (\( 15 \) sided polygon) is inscribed in a circle of radius \( 8\,\mathrm{cm} \). Calculate its area. Round the result to two decimal places.
\( 195.23\,\mathrm{cm}^2 \)
\( 97.62\,\mathrm{cm}^2 \)
\( 13.02\,\mathrm{cm}^2 \)
\( 24.40\,\mathrm{cm}^2 \)

1003055007

Level: 
B
In a regular decagon (\( 10 \) sided polygon) the length of the side is \( 4\,\mathrm{cm} \). Which of the given numbers most accurately expresses fits its area most accurately?
\( 123\,\mathrm{cm}^2 \)
\( 12\,\mathrm{cm}^2 \)
\( 55\,\mathrm{cm}^2 \)
\( 185\,\mathrm{cm}^2 \)