Geometry
# Congruent and Similar Triangles

$ABC$ and $DEF$, if we know that $AB = EF, BC = DE$ and $\angle ABC = \angle DEF$, are the triangles congruent?

In triangles$x=21,$ $y=14,$ $\alpha={35}^\circ,$ and $\beta={75}^\circ.$ Which condition would mean that the two triangles are similar?

In the above diagram,**Note:** The above diagram is not drawn to scale.

$($of diameter $d)$ placed a distance $r$ in front of your eye?

Did you know you can approximate the diameter of the moon with a coinIf the distance between the moon and your eye is $R,$ what is the diameter of the moon?

$\triangle ABC$ is similar to $\triangle DEF$, and the ratio of their areas is $9:25.$ If the length of $\overline{DE}$ is $60,$ what is the length of $\overline{AB}$?

Triangle