Question

In a triangle ABC, ∠A = 70°, ∠B = 80° and D is the incentre of ΔABC. ∠ACB = 2x° and ∠BDC = y°. The values of x and y, respectively are

A) 15, 130 B) 15, 125 C) 35, 40 D) 30, 150

Answer 1

Answer:

∠C = 180 - (∠A + ∠B)

∠C = 180 - 150

2x = 30

x = 15°

∠BDC = 90° +1/2 ∠A

∠BDC = 90° + 1/2× 70°

∠BDC = 90° + 35°

∠BDC = 125°

So value of x and y are = 15°, 125°

So the correct option is B) 15,125.

Hope this helps!

Answer 2

angle C=180-150(70+80)

=30

2x=30

x=30/2

x=15

90+1/2 angle A

90+1/2*70

90+35

y=125