Question

ABCD is a parallelogram in which angle ADC = 60° and angle ACB = 70° . find the measure of angle DCB , angle CAB and angle DAC​

Answer 1

Step-by-step explanation:

Ans. In quadrilateral ABCD we have

AC = AD

and AB being the bisector of ∠A.

Now, in ΔABC and ΔABD,

AC = AD

[Given]

AB = AB

[Common]

∠CAB = ∠DAB [∴ AB bisects ∠CAD]

∴ Using SAS criteria, we have

ΔABC ≌ ΔABD.

∴ Corresponding parts of congruent triangles (c.p.c.t) are equal.

∴ BC = BD.