Question

If a ray CD stands on a line ab then prove that angle acd +angle bcd =180

Answer 1

Step-by-step explanation:

construct a line CE perpendicular to AB

angle acd = angle ace + angle dec = 90 + angle dec ..... 1

angle bcd = angle ace - angle dec = 90 - angle dec ......2

on combing 1 and 2

angle acd + angle bcd = 90 + angle dec + 90 - angle dec

since + dec - dec = 0,

angle acd + angle bcd = 90 +90 = 180