Answers to the first volume of the eighth grade mathematics textbook published by Su Ke Edition (1)
Page 8 of the exercise textbook 1 answer.
Tip: The congruent numbers in the figure are:
6 small triangles;
2 largest triangles;
3 parallelograms;
Six pentagons and so on.
Solution to the second question on page 8 of the exercise textbook: the answer is not unique, as shown in figure 1.
Answers to the first volume of the eighth grade mathematics textbook published by Su Ke Edition (II)
The answer to the question on page 10 of the exercise textbook 1.
Solution: equilateral: AB=CD, BC= DA, AC=CA.
Equal angle:? BAC=？ DCA，？ B=？ d，？ ACB=？ CAD？ Bad =? DCB。
The answer to the second question on page 10 in the exercise textbook.
Solution: Rotate △ABC counterclockwise around point O for two turns 120? , can coincide with two triangles, fold △ABC along BC line, can coincide with the triangle below it, and rotate the folded triangle counterclockwise around point O twice 120? Can coincide with the other two triangles; Similarly, rotate △DOE twice counterclockwise around point O 120? , can coincide with two triangles, fold △DOE along the straight line OE, can coincide with the triangle on its left, and rotate the folded triangle counterclockwise around the O point twice 120? Can coincide with the other two triangles.
Answers to the first volume of the eighth grade mathematics textbook published by Su Ke Edition (III)
The answer to the question on page 14 of the exercise textbook 1.
Solution: Figures ① and ④ are congruent triangles. Because these two triangles have two groups of corresponding sides, and the angles enclosed by the corresponding sides are also equal, it can be judged that these two triangles are congruent according to SAS. For the same reason, Figures ③ and ⑤ are also congruent triangles.
The answer to the second question on page 14.
It is proved that in △ABE and △ACD,