Question

which angles are complementary to ∠dfe? select all that apply. ∠efb ∠efa ∠cfd ∠bfc

Explanation:

Step1: Define complementary angles

Complementary angles sum to $90^\circ$.

Step2: Identify right angle

$\angle AFB$ is a right angle, so $\angle AFD = 90^\circ$. This means $\angle DFE + \angle EFA = 90^\circ$, so $\angle EFA$ is complementary to $\angle DFE$.

Step3: Use vertical/linear pairs

$\angle BFC$ is vertical to $\angle AFD$, so $\angle BFC = 90^\circ$. Thus $\angle DFE + \angle CFD = 90^\circ$, so $\angle CFD$ is complementary to $\angle DFE$.

Step4: Eliminate non-complementary angles

$\angle EFB > 90^\circ$, so it cannot be complementary. $\angle BFC = 90^\circ$, so it cannot sum with $\angle DFE$ to $90^\circ$.

Answer:

$\angle EFA$, $\angle CFD$