Question

find the value of unknown in the following figures:​

Answer 1

Answer:

140°

Step-by-step explanation:

extende AC to E

and let angle ACE = x

in angle DBC and ABC

angle DBC+angle ABC = 180°. ( linear pair)

= 85°+angle ABC=180°

angle ABC= 180-85

= 95°

now in ∆ABC

angle BAC +angle ABC + angle ACB = 180°. ( angle sum property)

45°+95°+ angle ACB = 180°

140° + angle ACB = 180°

angle ACB = 180-140

= 40°

now in angle BCE and angle ACB

= angle ACB + angle BCE = 180°. ( linear pair)

= 40° + angle BCE = 180°

= angle BCE = 180-40

= 140°

hence angle BCE = X= 140°