Holding height fixed while displacement changes shows shear strain as geometry. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
One metre over four gives one fourth strain
Hold layer height at 4 metres. A displacement of 1 metre gives shear strain 1/4.
1/4=41
Two metres over four gives one half strain
The same height with displacement 2 metres gives strain 1/2.
2/4=21
Three metres over four gives three fourths strain
Displacement 3 metres gives strain 3/4. The scan stops before strain reaches one.