As shown in figure (1), stack the right angle vertex C of two right angle trigonometric rulers together, (1) If ∠ DCE = 35 °, ACB=______ If ∠ ACB = 140 °, then ∠ DCE=______ (2) guess the special relationship between ∠ ACB and ∠ DCE, and explain the reason; (3) as shown in figure (2), if the apex a of 60 ° acute angle of two same right angle trigonometric ruler coincides, then what is the relationship between ∠ DAB and ∠ CAE, please explain the reason

As shown in figure (1), stack the right angle vertex C of two right angle trigonometric rulers together, (1) If ∠ DCE = 35 °, ACB=______ If ∠ ACB = 140 °, then ∠ DCE=______ (2) guess the special relationship between ∠ ACB and ∠ DCE, and explain the reason; (3) as shown in figure (2), if the apex a of 60 ° acute angle of two same right angle trigonometric ruler coincides, then what is the relationship between ∠ DAB and ∠ CAE, please explain the reason

(1) As the result of DCE = 35, the DCE = 35 ′