冀教版七年级数学下册第九章三角形 单元测试题

适用年级:初一
试卷号:575171

试卷类型:单元测试
试卷考试时间:2019/1/31

1.单选题(共7题)

1.
已知a、b、c是△ABC的三条边长,化简|a+b-c|-|c-a-b|的结果为(   )
A. 2a+2b-2c B. 2a+2b    C. 2c D. 0
2.
如图所示,BP是△ABC中∠ABC的平分线,CP是△ABC的外角∠ACM的平分线,如果∠ABP=20°,∠ACP=50°,那么∠A+∠P的度数为(  )
A.60°B.70°C.80°D.90°
3.
下列长度的三条线段可以组成三角形的是(  )
A.3,4,2B.12,5,6
C.1,5,9D.5,2,7
4.
如图,ACBCCDABDEBC,垂足分别为CDE,则下列说法不正确的是(  )
A.AC是△ABC的高B.DE是△BCD的高
C.DE是△ABE的高D.AD是△ACD的高
5.
如果一个等腰三角形两边的长分别是1,5,那么它的周长是(  )
A.7B.11
C.7或11D.以上选项都不对
6.
符合条件2∠A=2∠B=∠C的△ABC是(  )
A.直角三角形B.锐角三角形
C.钝角三角形D.不能确定
7.
如图,将三角尺的直角顶点放在直线a上,a∥b,∠1=50°,∠2=60°,则∠3的度数为【   】
A.50°B.60°C.70°D.80°

2.选择题(共1题)

8.

阅读下文并回答问题。

    There are 24 solar terms (节气) in China, and the Grain Rain(谷雨) is one of them. It falls on April 19 this year.

    This solar term is called the Grain Rain because it is known for “rain” that helps the grain grow. From its name, we can guess it means a time of more rain. So if you go out in the next two weeks, you may need to bring an umbrella with you.

    But this is a great time for planting crops. If you miss the time for planting during the Grain Rain, you will feel sorry later. So maybe you can try to plant some flowers or vegetables in your garden. When the spring rain falls, farmers begin to grow crops (庄稼). Farmers often say, “Spring rain is as precious (珍贵的) as oil.” It brings farmers hope for a good year ahead.

    There are also many interesting customs during the Grain Rain. In the northern part of China, people like to eat Chinese toon (椿芽) mixed with eggs. The food made during the Grain Rain tastes wonderful and is good for your stomach. In the southern part of China, the tea leaves are picked during the time. They are called Grain Rain tea, which is famous for its freshness and sweet smell.

3.填空题(共5题)

9.
如图所示,∠A与∠B的度数之比为2:3,则∠A=________°.
10.
如图,在△ABC中,AD平分∠BACBE是高,∠BAC=50°,∠EBC=20°,则∠ADC=________°.
11.
如图,在△ABC中,AB=5 cm,BC=3 cm,BM为中线,则△ABM与△BCM的周长之差是________ cm.
12.
已知△ABC的两条边的长度分别为3 cm,6 cm,若△ABC的周长为偶数,则第三条边的长度是________ cm.
13.
直角三角形两锐角的平分线相交,所得的钝角是________°.

4.解答题(共5题)

14.
如图,AD为△ABC的中线,BE为△ABD的中线.
(1)若∠ABE=15°,∠BAD=40°,则∠BED=________°;
(2)请在图中作出△BEDBD边上的高EF
(3)若△ABC的面积为40,BD=5,则点EBC边的距离为多少?
15.
在△ABC中,已知∠A-∠B=30°,∠C=4∠B,求∠A,∠B,∠C的度数,并判断这个三角形的形状.
16.
已知在△ABC中,AB>AC,∠AEF=∠AFE,延长EFBC的延长线交于点G,试说明:∠G (∠ACB-∠B).
17.
如图,△ABC中,ADBC边上的高,AE是∠BAC的平分线,∠EAD=5°,∠B=50°,求∠C的度数.
18.
如图所示,已知△ABC的周长为21 cm,AB=6 cm,BC边上中线AD=5 cm,△ABD的周长为15 cm,求AC的长.
试卷分析
  • 【1】题量占比

    单选题:(7道)

    选择题:(1道)

    填空题:(5道)

    解答题:(5道)

  • 【2】:难度分析

    1星难题:0

    2星难题:0

    3星难题:0

    4星难题:0

    5星难题:0

    6星难题:9

    7星难题:0

    8星难题:7

    9星难题:1