Question

triangle def is an isosceles, so ∠def ≅ ∠dfe
angle def measures 75°. what is the measure of
angle cfd?
105°
125°
150°
165°

Explanation:

Step1: Find the measure of ∠DFE

Since ∠DEF = ∠DFE and ∠DEF = 75°, so ∠DFE = 75°

Step2: Use the linear - pair property

∠CFD and ∠DFE form a linear pair. The sum of angles in a linear pair is 180°.
Let \(x=\angle CFD\). Then \(x + 75°=180°\)

Step3: Solve for \(x\)

\(x=180° - 75°=105°\)

Answer:

105°