Question

Given triangle ABC, know C > B , bisector is AD, 7B = 4C and ADC = 75 degrees . Calculate the angles of triangle ABC?

Answer 1

Answer:

Step-by-step explanation:

Given: ∠B=∠C,∠DAX=70∘

 and ray AX bisects exterior ∠DAC

To find: ∠ACB

Solution: Since ray AX bisects exterior ∠DAC

∴∠CAX=∠DAX=70  

Now, By Exterior angle sum property of triangle, we have

∠DAC=∠ABC+∠ACB

⇒∠DAX+∠CAX=∠ACB+∠ACB[∵∠B=∠C]

⇒70∘ +70∘

=2∠ACB

⇒∠ACB=(2)

140 ∘  ⇒∠ACB=70∘