Measuring V-groove

[[Me...]]

I've been tasked with measuring a V-groove on the outside of a cylinder. It is 1.8 mm wide at one end and .8 mm at the other. it also has a 1.5* depth angle . They want me to measure the overall angle and the depths at the beginning and the end of the groove. I've suggested other ways to measure this but the engineer is insisting I measure it on the CMM.. Any suggestions ?