急~有數學唔識做？？

圖片參考：http://i256.photobucket.com/albums/hh172/hkchelsea_united/20101006_1.png


圖片參考：http://i256.photobucket.com/albums/hh172/hkchelsea_united/20101006_2.png


圖片參考：http://i256.photobucket.com/albums/hh172/hkchelsea_united/20101006_3.png


希望幫到你!
有錯請指正!
有問題歡迎提出!

Question on the far left:

OQ = OP (radius of the circle)
Triangle POQ is isosceles triangle, angle OPQ = angle OQP = 53º
Angle POQ = 180º - 53º - 53º = 74º
Angle PRQ = 1/2 of angle POQ = 1/2(74º) = 37º
(Sector angle is twice inscribed angle subtended by the same arc.)

Angle PRQ = y = 37º


Question 6:
Angle OSR = angle ORS = 39º (OSR is isosceles triangle)
RSP = 90º (inscribes angle subtended by a semicircle is 90º)
Angle OSP = 90º - 39º = 51º
Angle SPO = angle OSP = 51º (OSP is isosceles triangle)
SP is parallel to OQ
Angle SPO = angle POQ = 51º (Alternate angle)
z = angle POQ = 51º


Question 1:
Angle ACB = 180º - 125º = 55º
Angle BOA = 2x (Angle ACB) = 2(55º) = 110º
(Sector angle is twice inscribed angle subtended by the same arc.)
x = 360º - Angle BOA = 360º - 110º = 250º