Chapter 4.6, Problem 3CE

To determine

To write: the reason for given key step of the proof.

Answer to Problem 3CE

Explanation of Solution

Given information:

Given figure,

Prove: $\angle 3\cong \angle 4$

Given key steps of proof:

  $\Delta LOB\cong \Delta JOB$

  $\angle 1\cong \angle 2$

  $\Delta LBA\cong \Delta JBA$

  $\angle 3\cong \angle 4$

Calculation:

Prove that:

  $\angle 3\cong \angle 4$

Key steps of proof are as follows:

$\Delta LOB\cong \Delta JOB$

1. (side-side-side postulate)
$\angle 1\cong \angle 2$ (corresponding $\angle s$ of $\cong \Delta s$ are $\cong$
2. )
$\Delta LBA\cong \Delta JBA$
3. (side-side-side postulate)
$\angle 3\cong \angle 4$ (corresponding $\angle s$ of $\cong \Delta s$ are $\cong$
4. )