The intersection of synchronous analysis and evaluation answers (1) in the second volume of seventh grade mathematics
Learning synchronization
( 1)
1、A
2、 16?
3. hint: do it? What is the diagonal of AOB? Complementary angle of AOB
4、? 2=55? ,? BOD= 125？ . Tip: Settings? So 2=x? 1=70? +x，by？ 1+? 2= 180? Available x=55?
(2)
1、D
2. Tip: The intersection points m and n are perpendicular to the straight line AB, respectively.
3、 30?
(3)
1、D 2、B
3、? 3,? 5,? 2,=,
4、? 1 and? 2 is the congruence angle formed by CD cutting straight lines OA and OB; ? O and? 1 is the inner angle of the same side formed by the line OB and CD being cut by OA; ? O and? 2 is the tangent angle formed when the straight line OA and CD are cut by OB.
Ability improvement
1、D 2、C
3、? AED？ AEF； ? CEO，？ FEO？ Deao
4、30? Or 150? Tip: where is the sub-ray OB? AOC internal and external.
5、 30? 75?
6、( 1)? BOD， 180； (2) 180?
Synchronous analysis and evaluation answers of the second volume of seventh grade mathematics (2) the nature of parallel lines
Synchronous learning
( 1)
1、 180
2、①②③④
3. south by west 37?
4、 120? Hint: Because? 1=? 2=70? A/b can be known from the fact that two wrong angles are equal and two straight lines are parallel.
(2)
1, C. Hint: A proposition is a statement that makes a judgment on one thing, regardless of whether this judgment is correct or not.
2、B
3. The title is abbreviated
(1) If there are two points on a plane, a straight line passes through them. The topic is: there are two points on a plane; The conclusion is that there is only one straight line through these two points.
(2) If two sums are equal, then their complementary angles are equal. The topic is: the two angles are equal, and the conclusion is: their complementary angles are equal.
(3) If two angles are internal angles, then they are equal. The topic is: Two angles are internal angles; The conclusion is that they are equal.
4、? ABC，？ BCD, the definition of vertical; ? EBC？ The dislocation angles in BCF are equal and the two straight lines are parallel.
Ability improvement
1、B
2、 70? 1 10? Tip:? GEF=？ DEF=？ EFG=55？ ,? AEG= 180？ -552=70? , known AD//BC,? BGE=？ GED= 1 10？ .
3.AB//CD tip: Certificate? ABC=？ BCD, get AB//CD.
Synchronous analysis and evaluation of the second volume of seventh grade mathematics (3) Chapter V Ability test
1、2、3、4、5、6、
BDABDA
7、? Bank of China; ? AOE； ? AOE？ BOF .
8、 1 10
9. The title is abbreviated
(1) AD, (2) BC 2)AB, DC
(3) Cab, DCA(4) ADC, DAB or DCB, ABC.
10、? Cab; ? Cab; CD, the internal dislocation angles are equal, and the two straight lines are parallel.
1 1、? 3. Two straight lines are parallel and the same angle is equal; DG, the internal dislocation angles are equal and the two straight lines are parallel; ? AGD, two straight lines are parallel and complementary; 1 10? .
12、( 1)? A+？ P+？ C=360？ ; (2)? P=？ A+？ c； (3)? C=？ A+？ p .
13, title omitted.
(1) omitted
(2)ab-b，ab-b，a b-b；
(3) the grassland area is ab-B.