Net of a sphere in six triangles, with figures and sums
Clustered cubes and circles, columns of fractions, and the unfolded sphere
The sheet pairs geometric constructions with numerical work. On 177v are clustered cubes, small groups of three circles, and columns of fractions worked in ink, while a caption on 180r states that a b c d form the unfolded net (spoglia) of a sphere made of six triangles. Faint red-chalk framing lines underlie the right-hand leaf. Further untranscribed jottings accompany the drawings.
On this page
Unfolding a sphere into six triangles
The caption identifies a b c d as the spoglia, or flattened net, of the sphere composed of six triangles. It describes developing the curved spherical surface into a planar figure of triangular gores.
Columns of fractions
The lower left of 177v carries stacked columns of fractional calculations set beside the geometric sketches. They read as working notes rather than continuous prose.
Clustered cubes and circle groups
The centre of 177v shows small cubes gathered corner-to-corner and repeated triplets of tangent circles. They appear to be exploratory solid- and plane-geometry doodles.