$ABC$ and $DBC$ are both isosceles triangles on a common base$BC$ such that $A$ and $D$ lie on the same side of $BC$. Are triangles $ADB$ and $ADC$ congruent? Which condition do you use? If $\angle BAC=40°$ and $\angle BDC=100°$; then find $\angle ADB$.    

$△ABC$ and $△ABD$ are on a common base $AB$, $AC=BD$ and $BC=AD$ as shown in the figure and $△ABC\cong △ABD$.

$△ABC$ and $△ABD$ are on a common base $AB$ and $AC=BD$ and $BC=AD$ as shown in the figure and $△ABC\cong △ADB$.

$△ABC$ and $△ABD$ are on a common base $AB$, $AC=BD$ and $BC=AD$ as shown in the figure and $△ABC\cong △BAD$.

In the given figure, $△ABC$ is isosceles with $AB=AC$, $D$ is the midpoint of base $BC$. Is $△ADB\cong △ADC$?

Write the correct answer by choosing from the following (Yes / No/ Maybe)

In Figure, $△ABC$ is isosceles with $AB=AC$, $D$ is the midpoint of base $BC$.

State the three pairs of matching parts you used to arrive at your answer.

In Figure, $△ABC$ is isosceles with $AB=AC$. State if $△ABC\cong △ACB$. If yes, state three relations that you used to arrive at your answer.

Triangles $ABC$ and $DBC$ have side $BC$ common, $AB=BD$ and $AC=CD$. Are the two triangles congruent? State in symbolic form. Which congruence condition do you use? Does $\angle ABD$ equal $\angle ACD$? Why or why not?

By applying $\mathrm{SAS}$ congruence condition, state which triangle is congruent to$∆AOB$.