⊿ The degrees of the three internal angles of ⊿ABC are A, B and C, where a = 70,

As shown in the figure, O is the heart of ⊿ABC, ∠ BEC = ∠ 4-∠ 2 = (180-c)/2-b/2 = 90-c/2-b/2 = ≧.

∴AOCE is a quadrilateral inscribed in a circle,

∠CAE =∠Coe =∠2+∠7 = B/2+C/2 =( 180-A)/2 =( 180-70)/2 = 55。