數學題: In the figure, QR=16cm, SR=10cm and SU=8cm. Find the value of the unknown h
.
圖片參考：http://imgcld.yimg.com/8/n/HA05909411/o/701202190048613873438670.jpg
請數學高手!
2012-02-20 12:42 am
回答 (3)
2012-02-20 1:23 am
✔ 最佳答案
PQRS is a parallelogram.PS = QR = 16 cm (opp. sides of //gram)
and PQ = SR = 10 cm (opp. sides of //gram)
Let PU = y
Area of trapezium QRSU = Area of //gram PQRS + Area of ΔPUS
(RS + QU) * SU / 2 = PS * RV + PU * US / 2
(10 + 10 + y) * 8 / 2 = 16h + 8y / 2
80 + 4y = 16h + 4y
16h = 80
h = 5
參考: Adam
2012-02-20 1:34 am
那應該是平行四邊形吧!?
所以上面是直角三角形 30-60-90
>>角UPS=角PQR
>>所以平行四邊形面積=10*16*sin30=16*h
h=5
應該是這樣吧
2012-02-19 17:35:53 補充：
我英文真弱 SORRY~
所以上面是直角三角形 30-60-90
>>角UPS=角PQR
>>所以平行四邊形面積=10*16*sin30=16*h
h=5
應該是這樣吧
2012-02-19 17:35:53 補充：
我英文真弱 SORRY~
參考: me
2012-02-20 1:26 am
UQ // RS and angle U = 90 degree, so angle USR = 90 = angle USP + angle PSR.
But angle UPS + angle USP = 90,
so angle UPS = angle PSR
so triangle UPS is similar to triangle VSR
so VR/RS = US/PS
h/10 = 8/16
h = 5.
But angle UPS + angle USP = 90,
so angle UPS = angle PSR
so triangle UPS is similar to triangle VSR
so VR/RS = US/PS
h/10 = 8/16
h = 5.
收錄日期: 2021-04-16 14:03:46
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120219000051KK00486