trigo Q

Let b be the height of B above XY.b / BP = sin32°
b / 2 = sin32°
b = 2sin32°sin∠RAP = b / AB
sin∠RAP = 2sin32° / 7
∠RAP = 8.70839°
So ∠DAX = 180 - 90 - 8.70839 = 81.29161°Let d be the height of D above XY , then
d / DA = sin∠DAX
d / 3 = sin81.29161°
d = 3sin81.29161° = 2.965 cm then the height of C above XY
= d + b
= 2.965 + 2sin32°
= 4.025 cm

2012-07-28 00:27:16 補充：
Typing error : ∠RAP should be ∠BAP.