1.http://imageshack.us/photo/my-images/607/42886450986545903089767.jpg/
Q:Find the area of the shaded region PQRS.
2.http://imageshack.us/photo/my-images/163/52659150986551903089128.jpg/
Q:In the figure, the 4 smaller squares foem a lager square. Now join A , B , C and D with O respectively , and calculate the sum of 4 angles AOP, BOP
, COP and DOP.
3.http://imageshack.us/photo/my-images/502/53019050986537569757283.jpg/
Q:Referring to the figure, write down a pair of similar triangles and give reasons.