Help i don’t know

Which transformations could have occurred to map △abc to △a"b"c"? a rotation and a reflection a translation and a dilation a reflection and a dilation a dilation and a rotation

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.