BE right over here, so once again, we have 2 right triangles, we already know that 2 of the legs are congruent to each other, they both share the hypotenuse this hypotenuse is equal to its self, we know from the pythagorean theorm if you know 2 sides of a triangle, it determines the third side, so and we know 2 sides of both of these, so the third sides must be the same, so this side must be equal to that side so you could invoke SSS, Side Side Side, to show these 2 triangles are congruent or you actually didn't need to -have to good there you could have used a special case, the RSH case, where if you have a right triangle, so if you have the right triangle you have one set of sides that are congruent, and you have the hypotenuse that is congruent then you're also okay, you could use RSH to prove congruency as well, and so either way we know that triangle EBD, triangle EBD, is congruent to triangle EBF congruent to triangle EBF, we used Side Side Side here but you could have used RSH, let me write that