[幾何]MATHS~easy呀 20分!! 2日!!急!!

7)

angleQPD = 100
angle ACB = 25 ( alt. angles, AD//BC )

y = angleQPD + angleACB (ext. angle of triangle)
= 25 + 100


angleBDC = 100 - 25 = 75
angleCPD = 80 ( angles on st line )

BDC + CPD + X = 180 ( angle sum of triangle)
X = 25


8)
angle PRQ = 45 ( property of square)
angle ABR = 60
angle SAQ = ABR + PRQ ( ext. angle of triangle)

明唔明啊> < ??

2006-12-12 00:16:06 補充：
啊...第七題第二part錯左 = =應該系angleBDC = 90 - 25 = 65angleCPD = 80 ( angles on st line )BDC CPD X = 180 ( angle sum of triangle)X = 35

2006-12-12 00:16:20 補充：
啊...第七題第二part錯左 = =應該系angleBDC = 90 - 25 = 65angleCPD = 80 ( angles on st line )BDC CPD X = 180 ( angle sum of triangle)X = 35

2006-12-12 00:16:31 補充：
啊...第七題第二part錯左 = =應該系angleBDC = 90 - 25 = 65angleCPD = 80 ( angles on st line )BDC CPD X = 180 ( angle sum of triangle)X = 35

Q7

x + 90度 = 100度 + 25度 (ext. angle of triangle)
x = 35度

y = 90度 + x度 (ext. angle of triangle)
y = 90度 + 35度
y = 125度


Q8.

角ABR = 60度 (vert. opp angles)
角BRA = 45度
角SAQ = 60度 + 45度
角SAQ = 105度

2006-12-12 00:11:18 補充：
Q8.角ABR = 60度 (vert. opp angles)角BRA = 45度角SAQ = 60度 45度 (ext. angle of triangle)角SAQ = 105度