The hindlegs emerge pretty soon in the larval development of the tadpole. The front legs are not visible but develop with the same pace as the hindlegs. Because the frontlegs in a tadpole are hidden in a pouch, they only seem to 'suddenly emerge'.
Frog hind legs are more important for jumping. They are powerful and designed for pushing off the ground quickly and providing the necessary force to propel the frog into the air. The frog's hind legs are able to extend and flex rapidly, allowing them to generate the force needed for a strong jump.
Frogs don't really sit up like toads do. They are more flat.
no
their back legs
Yes they have forelegs and hindlegs
their forelegs and hindlegs
Between the hindlegs just like a cow.
Tadpoles typically emerge from eggs in the water shortly after they are laid by the adult frog. The timing can vary depending on the frog species and environmental conditions, but generally it takes a few days to a couple of weeks for tadpoles to hatch.
A large number of muscles exist in the frog's body. Some of the most important include the gastrocnemius and the external obliques. The gastrocnemius serves to provide the pushing power needed in jumping, while the external obliques serve to compress the lungs and force air out, helping the frog breathe.
"Emerge" is a verb.
The past tense of "emerge" is "emerged".
Spadefoot toads (several species) inhabit nearly all desert areas of the American southwest. They spend almost their entire lives underground and only emerge after a heavy rain.