摘要：22．In the picture,if ∠AOB＝90º ,OD is the angular bisector of ∠BOC and OE is the angular bisector of ∠AOC, then ∠EOD＝( ) (A) 30º (B) 45º (C) 50º (D) 60º
网址：http://m.1010jiajiao.com/timu3_id_639563[举报]
In the trapezium（梯形）ABCD，AD∥BC，point E is midpoint（中点）of the AD，point F is midpoint of the BC，EF=
（BC-AD），the result of the∠B+∠C is（ ）
| 1 |
| 2 |
| A、90° | B、100° |
| C、110° | D、120° |
As shown in the diagram（如图），the triangle PQR has PR=14cm and PQ=10cm．The side RQ produced meets the perpendicular PS at S，so that QS=5cm．The perimeter（周长） of triangle PQR is
In the figure1，ABCD is a diamond，points E and F lie on its sides AB and BC respectively，such that