Question

if ∠cdf ≅ ∠edf and cf = 7, what is ef? ef =

Explanation:

Step1: Identify congruent triangles

Since $\angle CDF\cong\angle EDF$, $\angle C\cong\angle E = 90^{\circ}$ and $DF$ is common to both $\triangle CDF$ and $\triangle EDF$. By the Angle - Angle - Side (AAS) congruence criterion, $\triangle CDF\cong\triangle EDF$.

Step2: Use property of congruent triangles

In congruent triangles, corresponding sides are equal. Since $CF$ and $EF$ are corresponding sides of congruent triangles $\triangle CDF$ and $\triangle EDF$, and $CF = 7$, then $EF=CF$.

Answer:

$7$