Similar Triangle Unknown Length

Similar Triangles can be used to find the distance across the river. Review the picture.  Find the missing side measurement in the picture using a proportion.

• x = 900 m

• 25 m

• x = 25 m

• x = 0.04 m

Fill in the similarity statement for these two triangles.
ΔLMN ~ 

• ΔGEF

• ΔEFG

• ΔFEG

• ΔGFE

Based on the drawing, which of the following statements is true?

• The triangles are similar because the lengths of the sides are congruent.

• The triangles are not similar because the corresponding angles are not congruent.

• The triangles are similar because the corresponding angles are congruent.

• Can not determine if the triangles are similar because the scale factor is unknown.

The Gateway Arch in Missouri casts a 120 foot shadow while a 16 foot pole casts a 4 foot shadow. How tall is the Arch?

• 30 feet

• 360 feet

• 480 feet

• 600 feet

Which conditions must be met for two triangles to be similar?

• Corresponding angles are congruent, and corresponding sides are proportional.

• Corresponding angles are congruent, and corresponding sides are congruent.

• Corresponding angles are unequal, and corresponding sides are proportional.

• Corresponding angles are proportional, and corresponding sides are congruent.

Figure Y is a dilation of Figure X.Which number best represents the scale factor used to change Figure X into Figure Y?

• 0.25

• 1.5

• 4

• 4.5

How do these triangles appear to be similar?
(Hint: Look for non-labeled parts!)

• AA

• SAS

• SSS

• Not Similar

Find the missing length.

• 4

• 10

• 8

• 12

Are the following triangles similar? If so, which postulate or theorem justifies this?

• Yes, by AA

• Yes, by SAS

• Yes, by SSS

• Not similar

Are the following triangles similar? If so, which postulate or theorem justifies this?

• Yes, by AA

• Yes, by SAS

• Yes, by SSS

• Not similar