in the given figure BC = CD angle find angle ACB
Answers
Answer:
angle c is 74⁰
Step-by-step explanation:
The process is explained in the above pic
Hope it helps you !
Given:
A figure in which BC = CD, angle ADC = 116°, angle EAD = 138°.
To find:
angle ACB.
Solution:
As we know that the sum of all angles on one side of a straight line is equal to 180°.
Thus, from the figure we have,
angle ADC + angle BDC = 180°
116° + angle BDC = 180°
angle BDC = 180° - 116°
angle BDC = 64°
Also,
angles opposite to equal sides are equal, so,
as given,
BC = CD
Hence,
angle BDC = angle DBC = 64°
Now,
In a triangle DCB,
angle BDC + angle DBC + angle BCD = 180°
(some of the interior angles of a triangle is 180°)
64° + 64° + angle BCD = 180°
128° + angle BCD = 180°
angle BCD = 180° - 128° = 52°
angle BCD = 52°..(i)
Now,
angle EAD + angle DAC = 180°
138° + angle DAC = 180°
angle DAC = 180° - 138° = 42°
angle DAC = 42°
Also, in a triangle ADC,
angle DAC + angle ADC + angle ACD = 180°
42° + 116° + angle ACD = 180°
angle ACD = 180° - 158° = 22°
angle ACD = 22°.. (ii)
Now,
angle ACB = angle ACD + angle BCD
angle ACB = 22° + 52° (from i and ii)
angle ACB = 74°
Hence, angle ACB is 74°.