Question

In Fig. 10.38, 2 ABC = 69, ZACB = 31°, find
BDC.
D​

Answer 1

In △ABC

∠BAC+∠ABC+∠ACB=180

(Angle sum property)

∠BAC+69 +31 =180

∠BAC=180 −100 =80

For segment BADCB,

VBDC and ∠BAC are angles in the same segment. So, they must be equal

∴ ∠BDC=∠BAC (Angles in the same segment are equal) ∠BDC=80