Question

In triangle ABC, D is a point on BC,
such that AB=BD, ADEDC ,then the ratio of
angle BAC and angle ACD is ? *
O 1:2
O 2:1
O 1:3
O 3:1​

Answer 1

Answer:

Here, AB,BD,AD are sides of a triangle. These sides are given equal. Hence the triangle is an equilateral triangle.

Thus, ∠ADB=60

∘

In △ADC,

AD=CD

Thus, ∠ADC=∠ACD=y (Isosceles triangle property)

Now, ∠ADB=∠ADC+∠ACD

60=y+y

y=30

∘

∠ACD=30

∘

∠ADC+∠ADB=180 (Angles on a straight line)

60+∠ADC=180

∠ADC=120

∘

Hence,

∠C

∠ADC

=

30

120

∠C

∠ADC

=4:1