Question

ABCD is a parallelogram in which ∠DAB = 70o and ∠CBD = 55o . Find ∠CDB and ∠ADB.

Answer 1

IN //gm ABCD
∠DAB =∠BCD
∴∠BCD =70°
now,
IN ΔBCD,
∠CBD+∠BCD+∠CDB=180°          (ASP)
55°+70°+∠CDB=180°
∴∠CDB=55°

∠CBD=∠ADB            (ALTERNATE INTERIOR ∠LE)
∴∠ADB=55°