Is there a geometry course in the first year of junior high school in 94?

No, I didn't start my geometry class until the second year of junior high school. Then there is the third year of junior high school. It's all plane geometry.

There are also many courses in the first year of junior high school in '94, including mathematics, Chinese, English, history, geography, and politics. Chemistry and Physics are taught after the second and third years of junior high school, and Physiology and Hygiene are also taught after that.

Geometry application problem for junior high school: There are two points A and B on the known line segment A, ...... BIt is known that there are two points A and B on the line segment A, and AB=12cm, and the point C is also on the line A and the distance from point B is 4cm, D is the AC emphasis, and E is the midpoint of BC, so find the length of the line segment De. **Wait!!

If it's good, add points because CB=4cm, AB=12cm

So ac=ab-cb

8cm because d is the midpoint of ac, ac=8cm

So dc=1 2ac

4cm and because E is the midpoint of CB, BC=4cm, CE=1 2BC

2cm so de=dc+de6cm

In '94, the general geometry class was added in the second year of junior high school.

Because CB=4cm, AB=12cm

So ac=ab-cb

8cm because d is the midpoint of ac, ac=8cm

So dc=1 2ac

4cm and because E is the midpoint of CB, BC=4cm, CE=1 2BC

2cm so de=dc+de6cm

There is no geometry course in the first year of junior high school, and there is no geometry course until the second year of junior high school.

I think that the angle cef = 20 degrees since the inner angle of the quadrilateral is 360 degrees, the angle b is 60 degrees eaf, and the angle bae is 20 degrees, and in the rhombus, the opposite angles of the rhomboid are equal, so: with 360 degrees - (2 times the angle eaf 60 degrees) = 240 degrees; Then use 240 2 = (2 times the angle ECF = 120 degrees); And because the angle EAF = 60 degrees, the triangle AEF is an equilateral triangle. Therefore, the angle AFE=60 degrees; Because the angle BAD=angle ECF=120 degrees, the angle FAD=40 degrees; Since the inner angle of the triangle is 180 degrees, the angle AFD = 80 degrees; So the angle efc = 40 degrees So the angle cef = 20 degrees.