Current location - Training Enrollment Network - Mathematics courses - The last question in the mid-term evaluation test paper of the seventh grade mathematics teaching in Chongqing No.1 Middle School (Part Two)
The last question in the mid-term evaluation test paper of the seventh grade mathematics teaching in Chongqing No.1 Middle School (Part Two)
By ∠ABF=∠AFB, ∠AFC=∠ACF:

AB=AF=AC

So ∠ABD=∠ACD

Then ∠1+∠ Abd = ∠ ADC = ∠ AFC+∠ 2 = ∠ ACF+∠ 2 = ∠ ACD+2 ∠ 2.

Therefore ∠ 1=2∠2.

Similarly < 3 = 2 < 4.