# Similar triangles

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##### Intros

##### Examples

###### Lessons

- Determine if the triangles are similar.

- Which triangles are similar?

Triangle Angles Sides $\Delta$ABC $\angle$A =90°

$\angle$B =45°

$\angle$C =45°AB=12.5

BC=17.7

AC=12.5$\Delta$DEF $\angle$D =90°

$\angle$E =45°

$\angle$F =45°DE=10

EF=14.2

DF=10$\Delta$GHI $\angle$G =90°

$\angle$H =60°

$\angle$I =30°GH=13.8

HI=27.6

GI=23.9$\Delta$JKL $\angle$J =90°

$\angle$K =45°

$\angle$L =45°JK=5

KL=7.1

JL=5 - $\Delta$ABC and $\Delta$DEF are similar triangles. Calculate the missing side length.

- A wood made ramp needs one supporting beam (y) for reinforcement. How long should the supporting beam be?