a pentagon ABCDE, ABis parallel to DC and A:E:D=3:4:5.find angle E
A:E:D = 3:4:5
let the common multiple be x
THEREFORE 3x + 4x + 5x ( the base angles of the pentagon are 90 degree each and the total sum of angles is 540 Therefore 12 x = 120 degree therefore 540 - 90 + 90 = 360 degree)
therefore x = 10 degree
therefore angle E = 3 x 12 = 36 degree
let the common multiple be x
THEREFORE 3x + 4x + 5x ( the base angles of the pentagon are 90 degree each and the total sum of angles is 540 Therefore 12 x = 120 degree therefore 540 - 90 + 90 = 360 degree)
therefore x = 10 degree
therefore angle E = 3 x 12 = 36 degree