To show that two shapes are similar, follow these easy steps:

1. Look at the Angles: First, check if all the angles that match up in the shapes are the same. If they are, that’s a good sign!

2. Compare Side Lengths: Next, find out how long each side is. To do this, calculate the ratios of the side lengths that match. For the shapes to be similar, these ratios should all be equal.

3. Complete the Proportions: If you have triangle $ABC$ and triangle $DEF$, see if this is true: $\frac{AB}{DE} = \frac{BC}{EF} = \frac{CA}{FD}$.

If both of these things are true, then the shapes are similar!