Question

Look at the figure. How can you prove the triangles are congruent?
B
A
С
AABD - ACBD by the SSS Postulate.
AABD - ACBD by the SAS Postulate.
It is not possible to determine if the triangles are congruent

Answer 1

Answer: SSS Postulate

The tickmarks tell us which pairs of sides are the same length.

• AB = BC due to the single tickmarks
• AD = CD due to the double tickmarks

So far we have two pairs of congruent sides.

The third pair of congruent sides are the overlapping or shared sides BD = BD which is true by the reflexive property (anything is congruent to itself).

Overall we have three pairs of congruent sides allowing us to use SSS. Each "S" stands for "Side".