Reference answer
I. 1, 2, 3, 7, 4, 5,
6, 8, 7, equal and equally divided 8, 2 9, isosceles right angle 10,
2. 1 1, C 12, A 13, C 14, C 15, a.
16、B 17、A 18、D 19、B 20、D
Iii. 2 1, 1023 180④
22、① ②
23.① Prove that the root increases and the original equation has no solution ②.
24. Proof: Yes, ‖ is the midpoint,,,,
,,, is a rectangle.
25. simplify it: It doesn't matter when, when and the denominator.
When, when, the original form.
26. The square root of,, is.
27,,, primitive type
28. solution: let the bicycle speed be km/h and the car speed be km/h ... from the meaning of the problem, then. Answer: The bicycle speed is 12.5km/h, and the car speed is 37.5 km/h. ..
29、① 。 Prove that it is an equilateral triangle,,,,.
(2) When it is the midpoint, it satisfies the meaning of the question, it is the midpoint and an equilateral triangle, and bisecting,,, and is an equilateral triangle,,,,,
, , ,
Because.