3. A topographic map is shown below. х
1030
Y
1200
1120
z
Contour Interval: 20 m

it should be all of them because it asks if you included all of those in your answer

explanation:

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.

c. 75.7

i think that is the right

i do not get it   at all