Answer: By the Substitution property, the measure of angle ABC is equal to GHI.
Explanation: Since we have,
Angle ABC and angle DEF are congruent ⇒ = -------(1 )
Similarly, angle GHI and angle DEF are congruent⇒ = ---------(2)
On substituting the value of from equation (1) to the equation (2)
We get, =⇒
That is, the measure of angle ABC is equal to angle GHI.