>
数学
>
如图,E是边长为1的正方形ABCD的对角线BD上一点,且BE=BC,P为CE上任意一点,PQ⊥BC于点Q,PR⊥BE于点R,则PQ+PR的值是( )
A.
2
2
B.
1
2
C.
3
2
D.
2
3
人气:344 ℃ 时间:2019-11-21 01:30:57
解答
连接BP,过C作CM⊥BD,
∵S
△BCE
=S
△BPE
+S
△BPC
=BC×PQ×
1
2
+BE×PR×
1
2
=BC×(PQ+PR)×
1
2
=BE×CM×
1
2
,BC=BE,
∴PQ+PR=CM,
∵BE=BC=1且正方形对角线BD=
2BC
=
2
,
又BC=CD,CM⊥BD,
∴M为BD中点,又△BDC为直角三角形,
∴CM=
1
2
BD=
2
2
,
即PQ+PR值是
2
2
.
故选A.
推荐
E是边长为1的正方形ABCD对角线BD上一点,且BE=BC,P为CE上任意一点,PQ垂直BC于点Q,PR垂直BD于点R,则...
E是边长为1的正方形ABCD的对角线BD上一点且BE=BC,P为CE上一点,PQ垂直BC于点Q,PR垂直BE于点R
如图,E是边长为1的正方形ABCD的对角线BD上一点,且BE=BC,P为CE上任意一点,PQ⊥BC于点Q,PR⊥BE于点R,则PQ+PR的值是( ) A.22 B.12 C.32 D.23
在正方形ABCD的对角线BD上截取BE=BC,连结CE,P为CE上一点,PQ垂直于BC于Q,PR垂直于BE于R,若AC=a,则PQ+PR=______
正方形ABCD的对角线BC上取BE=BC,联结CE,P为CE任一点,PQ⊥BC,PR⊥BE,求PQ+PQ=1/2BD
对任意正整数n,设计一个程序求s=1+1/2+1/3+…+1/n的值.
《伤仲永》原文及翻译
I spend an hour reading books in the library every day.(改为同义句) ( ) ( ) me an hour ( ) ( )
猜你喜欢
英语翻译
someone is singing in the next room.同义句转换 ( ) ( ) someone singing in the next room
解二道一元二次方程,1.X²+3=2√3 ̄ X 2.3y²+4=y²
矩阵求导
Jim will play the violin at the party.的同义句 Jim __ __ __ play the violin at the party.
live on the 住在墙上?
The doctor says I am a little fat and can't eat too many.(改错)
小学四年级上册语文园地六的作文(写生活中的真事)
© 2024 79432.Com All Rights Reserved.
电脑版
|
手机版