Similarity Proofs

Are these triangles similar?
Known angles in Triangle 1:  40⁰,60⁰
Known angles in Triangle 2:  60⁰,40⁰

• Yes

• No

• There is not enough information to decide.

2 triangles are similar if _____________.

• their angles are congruent.

• their sides are congruent.

• their areas are equal.

• their perimeters are equal.

How many pairs of congruent angles in 2 triangles are needed to prove the 2 triangles are similar?

• 2 or 3

• 1

• 0

• only 3

If the triangles are similar, state how.

• SSS

• SAS

• AA

• Not similar

Similarity Ratio: _

• 2/3

• 1/2

• 2

• 3

Choose the similarity statement for the triangles.

• ΔMNL ∼ ΔOPQ

• ΔNOM ∼ ΔPQL

• ΔLMN ∼ ΔPQO

• ΔMLN ∼ ΔPQO

The triangles are similar by...

• SAS

• AA

• ASA

• SSS

What is the value of X?

• X=4

• X=6

• X=3

• X=2

What is the value of X and Y ?

• X=2.5 and Y=6.5

• X=6.5 and Y=2.5

• X=3 and Y=7

• X=2 and Y= 5

When proving these triangles similar, what would you write in for the missing reason?

• Math

• Corresponding sides are proportional

• Corresponding sides are congruent

• SSS similarity postulate