![](https://static.youtibao.com/asksite/comm/h5/images/m_q_title.png)
[单选题]
如图,在△ABC中,∠C=90°,点E是AC上的点,且∠1=∠2,DE垂直平分AB,垂足是D,如果EC=3cm,则AE等于()
A.3cm
B.4cm
C.6cm
D.9cm
![](https://static.youtibao.com/asksite/comm/h5/images/m_q_a.png)
A、3cm
![](https://static.youtibao.com/asksite/comm/h5/images/solist_ts.png)
A.3cm
B.4cm
C.6cm
D.9cm
A、3cm
A.66°
B.114°
C.123°
D.132°
A.∠BCB′=∠ACA′
B.∠ACB=2∠B
C.∠B′CA=∠B′AC
D.′C平分∠BB′A′
如图7-3-14所示结构,ABC段的抗弯刚度为,其余各段的抗弯刚度为EI,弹簧的刚度为k,在图示荷载及C点支座沉陷 共同作用下,若使结构中C支座不产生拉力,试确定沉陷 与弹簧刚度k应满足的关系.
A.30°
B.40°
C.50°
D.60°
A.2
B.3
C.4
D.5