I have a proof with a given of angle A is congruent to angle E, angles CBA is congruent to DBA. And B is the is the midpoint of line AE. (I can send pictures...) Could you give me the two column proof for this problem?
A, B, C, D are four points taken on a line in that order. AB = a, BC = b, CD = c. P is a point outside this line. Measures of angles APB = BPC = CPD = θ. Prove that cos^2(θ) = (a + b)(b + c)/4ac
in any triangle ABC,the angle bisector of angle A and perpendicular bisector of BC intersect.prove that they intersect on the circumcircle of the triangle ABC