Question

1. if m∠abd = 48° and m∠dbc = 78°, find m∠abc.

Explanation:

Step1: Identify angle - addition relationship

$\angle ABC=\angle ABD+\angle DBC$

Step2: Substitute given angle measures

$\angle ABC = 48^{\circ}+78^{\circ}$

Step3: Calculate the sum

$\angle ABC=126^{\circ}$

Answer:

$126^{\circ}$