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.