How can I get peaks values and distance between them indicated in the figure?

How can I get only the three peaks values corresponding their x-axis values indicated in the figure? And the horizontal distance between peak1 and peak2 or between peak 1 and peak3. How can I also get the FWHM of the maximum peak (here peak1). I don't need other peaks values apart from these three.

[Walter Roberson]

findpeaks() in part.