Calculate: |
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+ | = | |||
100 |
| 100 |
| 100 |
Take 52 per cent of 25 m / 82 ft. This is 13 m / 42.6 ft. Multiply this by the cosine of 9 degrees.
0.987 x 13 m = 12.8 m or equally in feet 0.987 x 42.6 ft. = 42 ft. Method 2. Multiply the ground distance by the slope angle cosine.
0.987 x 25 m = 24.6 m or equally in feet 0.987 x 82 ft. = 80.9 ft.
Add percentage readings as above and take the sum percentage of the corrected distance.
-------- 24,6m= 12,8m
52 ×
100
or equally in feet
-------- 80,9ft= 42ft
52 ×
100
This example shows that a slope angle of 9 degrees causes a correction of only
2.3per cent but when the slope angle is 35 degrees the correction means a reduction of about 18 per cent in the observed height.
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