# Martian Geometry Book 5

## Prhh1816d

### Hypothesis

Another segment of the road and more tiles, A shows the edge of the road here is in better condition. As B shows these tiles are mostly transverse, they go from one side of the road to the other approximately at right angles to the direction of the road. They are also about the same size and shape, like cobblestones at B at 2 o’clock.

## Prhh1817a

### Hypothesis

The lines show how straight the roads are, often not exactly straight. However many medieval roads were not this straight either.

## Prhh1818

### Hypothesis

A shows a road coming out of the hill at 10 and 12 o’clock, another road more eroded at 4 o’clock. B shows two roads, one going into a hollow hill at 4 o’clock. C shows two road intersections, one bordering a hollow hill at 1 o’clock, and another with a smaller hill at 4 o’clock. D shows a road going into a hill from a fork at 5 to 4 o’clock. E shows a road connecting to the edge of a hollow hill at 8 o’clock.

## Prhh1818a

### Hypothesis

The lines show how straight the roads are.

## Prhh1819

### Hypothesis

A shows more roads going into two hills and a crater, B shows these roads continuing down to another hill at 7 o’clock and across to 5 o’clock. C shows this road continuing to D at 5 o’clock and another hollow hill. E shows another road. The rectangle around C has more closeups of the road.

## Prhh1819a

### Hypothesis

The hollow hill at A has a patch on the roof at 7 o’clock, at 3 o’clock the road may have gone into the hill like a tube. B shows this road continuing on.

## Prhh1819b

### Hypothesis

A shows the edge of this road, B shows more of these tiles or cobblestones like Prhh1816d. They are again about the same size and shape. Between A and B the soil from the road side has been blowing onto the road obscuring these cobblestones.

## Prhh1820

### Hypothesis

A shows a road going into the hollow hill complex at 2 and 4 o’clock, B shows a road from the collapsed hollow hill at 8 o’clock going up to these hills. C shows more hollow hills connecting more by this pale soil as if it is one large habitat. D and E show more roads, F and G other parts of the hills.

## Prhh1820a

### Hypothesis

Parts of the image have been adjusted in brightness and contrast.

## Prhh1821

### Hypothesis

A shows more roads, they connect to a crater at 5 o’clock. B shows a road at 6 o’clock going into a small hollow hill, another at 4 o’clock going into a hollow hill. C shows a road connecting to a complex of hollow hills. D and E show many more roads connecting to hollow hills. F and G show roads connecting to the large crater. H shows a major intersection going up the image.

## Prhh1821aa

### Hypothesis

The lines show the roads are generally very straight.

## Prhh1821a

### Hypothesis

This shows a closeup of road material, it appears to have flaked off at A at 4 o’clock with a large segment at 8 o’clock extending into the side of the road. B shows the side of the road, C shows the road is covered by some material, perhaps this was the state of the intact road before this erosion. D shows a segment that has broken off.

## Prhh1821b

### Hypothesis

A further closeup of the road shows more possible cobblestones at A at 2 and 9 o’clock. B shows some cavities forming, C may show some larger tiles or plates.

## Prhh1821c

### Hypothesis

This segment appears to show higher grout between tiles , A shows some rectilinear grout. B shows some clear grout, under this there is  another layer of these. C shows a segment at 7 o’clock which continues over the step to the lower level, also one at 4 o’clock. D shows the grout is flusher with the ground at 4 and 9 o’clock, at 2 o’clock there is a step with the grout only on the middle step level. E shows the grout is much higher here, the tiles in between may be highly eroded or settling.

## Prhh1821d

### Hypothesis

A shows a higher area like a hill, the grout is more visible at 7 and 8 o’clock, at 3 o’clock it is less visible. B shows very rectilinear grout at 4 to 7 o’clock and over to D. At 3 o’clock the grout appears to go into the hill as if the hill is on top of this pattern over to C. The hill to the right of C also appears to sit on top of this grout pattern. D shows another step, the grout does not appear on the lower level.

## Prhh1821e

### Hypothesis

In this segment the grout is less straight, A shows bends in it. They may also be tubes or walls. B shows more rectilinear grout. C shows wavy grout like a double parabola.

## Prhh1821e2

### Hypothesis

Two connected parabolas are shown.

## Prhh1821f

### Hypothesis

In this area the grout is also visible, going into the higher terrain at the top of the image. A shows parallel ridges at 10 o’clock, connected like tiles at 1 o’clock second leg. B shows a gap between the grout at 9 o’clock, at to o’clock the horizontal grout extends through much of the image. C shows more of a mesh of grout.

## Prhh1821f2

### Hypothesis

The lines show how straight the grout is.

## Prhh1822

### Hypothesis

A shows a road connecting two craters at 10 o’clock, a small hill at an intersection at 6 o’clock, and a fork at 4 o’clock. B shows roads connecting to a hill at 6 o’clock, then over to a hill at 12 o’clock. C shows an intersection at 5 o’clock. D shows a road going to a crater on both sides at 1 and 2 o’clock, another road going down to a hill and crater from 10 to 7 o’clock. E and F show more roads.

## Prhh1823

### Hypothesis

A shows two roads going into a large hollow hill. B and I show roads in an eroded hollow hill complex. C shows two other roads going into this large hollow hill, this might be a good target to be explored for intact rooms. C at 4 o’clock show roads going into a crater. D shows another road, E shows a road going into a large eroded hollow hill complex at G. F and H show more roads.

## Prhh1823a

### Hypothesis

A shows a cavity on the edge of the hollow hill at 11 o’clock extending to 1 o’clock. B shows parallel edges of the pale wall boundary. At 3 and 7 o’clock is the exposed roof, the dark spots on it look like the skin is eroding away. C shows the edge of this pale roof segment, at 8 o’clock the hill has collapsed.

## Prhh1823a2

### Hypothesis

The hill’s shape can be described by four parabolas, even a fifth between the two top ones.

## Prhh1823b

### Hypothesis

The dark spots again appear to be eroded skin on the roof, A shows these patches and how they define the edge of the roof. B shows a clean edge of this dark material with a smooth pale wall under it like cement. C may be a road or tube.

## Prhh1823b2

### Hypothesis

Four parabolas are shown, the two at the bottom and the one on the left are exactly the same parabola.

## Prhh1824

### Hypothesis

A, B, and C are a complex of roads, this time going into the large pale area which might be a habitat. This again may be a good target for exploration. A at 7 o’clock has a road connecting to a smaller pale area around a crater, perhaps another habitat. D shows a straight road going to a small hill with an intersection at 9 o’clock. E may be collapsed parts of the large hollow hill area.

## Prhh1824aa

### Hypothesis

The lines show how straight the roads are.

## Prhh1824a

### Hypothesis

A shows a double wall from 11 to 1 o’clock, this may be a collapsed tube. At 10 o’clock is a break in the tube. B at 9 o’clock second large there are regular pillars or arches as the tube collapses. At 10 o’clock there appears to be a groove down the middle like a tube. C shows parallel walls, this may be a collapsed hill. Many of these are regular in shape and spacing like pillars. D may be an entrance to the hill.

## Prhh1824a2

### Hypothesis

Two parabolas are shown.

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