Symmetry and geometric transformations

1103162606

Level: 
C
The figure below shows two semicircles \( \widehat{AB} \) and \( \widehat{DA} \). Find the dilation scale factor if you know that the semicircle \( \widehat{DA} \) is the image of the semicircle \( \widehat{AB} \) in dilation with the centre \( C \).
\( -0.5 \)
\( 0.5 \)
\( -0.25 \)
\( 0.75 \)

9000149309

Level: 
C
Consider a dilatation which maps \(A\) onto \(B\). The center is the dilatation is \(S\). Find a correct statement.
The point \(S\) is on the line through the points \(A\) and \(B\).
The points \(S\), \(A\) and \(B\) form a right triangle \(ABS\).
The distance from \(S\) to \(A\) is smaller than the distance from \(A\) to \(B\).
The points \(S\), \(A\) and \(B\) form a triangle \(ABS\) with at least two sides of equal length.