國中數學直角坐標平面四邊形?
回答 (1)
2016-02-19 2:25 pm
記 d(-3,4) , c(-3,-2) , b(4,-2) , a(4,4) , 則矩形abcd = ab × bc = (4+2)(4+3) = 42,
△dCD = Cd × dD / 2 = (4+1)(0+3)/2 = 15/2
△aAD = aA × aD / 2 = (4-0)(4-0)/2 = 8
△bBA = bB × bA / 2 = (4-2)(0+2)/2 = 2
△cCB = cC × cB / 2 = (-1+2)(2+3)/2 = 5/2
四邊形ABCD面積為 42 - 15/2 - 8 - 2 - 5/2 = 22平方單位
△dCD = Cd × dD / 2 = (4+1)(0+3)/2 = 15/2
△aAD = aA × aD / 2 = (4-0)(4-0)/2 = 8
△bBA = bB × bA / 2 = (4-2)(0+2)/2 = 2
△cCB = cC × cB / 2 = (-1+2)(2+3)/2 = 5/2
四邊形ABCD面積為 42 - 15/2 - 8 - 2 - 5/2 = 22平方單位
收錄日期: 2021-04-18 14:31:07
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160219055206AASQxGj