close
標題:
Maths
發問:
P is a point inside a rectangle ABCD such that AP = 3, BP = 5 and CP = 7. Find the length of DP.
最佳解答:
Let the horizontal distance of P from A be a Let the horizontal distance of B from P be b Let the vertical distance of P from A be c Let the vertical distance of C from P be d AP^2=a^2+c^2=3^2=9 ... (1) BP^2=b^2+c^2=5^2=25 ...(2) CP^2=b^2+d^2=7^2=49 ...(3) DP^2=a^2+d^2 (2)-(1) => b^2+c^2-a^2-c^2=25-9 or b^2 - a^2 = 16 ... (4) (3)-(4) => b^2+d^2 - (b^2-a^2) = 49-16 or d^2+a^2=33 Therefore DP^2=33; DP = sqrt(33) = 5.74 2009-06-22 15:02:27 補充： I am assuming AB is horizontal
Maths
發問:
P is a point inside a rectangle ABCD such that AP = 3, BP = 5 and CP = 7. Find the length of DP.
最佳解答:
Let the horizontal distance of P from A be a Let the horizontal distance of B from P be b Let the vertical distance of P from A be c Let the vertical distance of C from P be d AP^2=a^2+c^2=3^2=9 ... (1) BP^2=b^2+c^2=5^2=25 ...(2) CP^2=b^2+d^2=7^2=49 ...(3) DP^2=a^2+d^2 (2)-(1) => b^2+c^2-a^2-c^2=25-9 or b^2 - a^2 = 16 ... (4) (3)-(4) => b^2+d^2 - (b^2-a^2) = 49-16 or d^2+a^2=33 Therefore DP^2=33; DP = sqrt(33) = 5.74 2009-06-22 15:02:27 補充： I am assuming AB is horizontal
此文章來自奇摩知識+如有不便請留言告知
其他解答:
文章標籤
全站熱搜
留言列表
