[填空题]
Mary (M) sits on the top of tk(h45p; p8-qy-ktpb vaibo f 7he Eastern side of the fvx ltrvwwrdb/ 61,j-8jp*;d Grand Canyon. Below her stands Peter (P), at the bottom of the canyon. It is known that the depth of the Grand Canyon is 1850 meters at this point. Nathan (N)lrt1j 6x v8f *-dr w/b;jdvp,w stands on the Western side of the bottom of the Canyon, with a distance of 2.5 km to Peter.
1.Write down the depth of the Grand Canyon, MP, in kilometers.MP= km
2.On the diagram, label the angle of elevation from N to M with an x.
3.Find the size of the angle of elevation from N to M. $^{\circ}$
4.Find MN, the distance in kilometers between Mary and Nathan. km
