Can you work out the dimensions of the three cubes?
Which of the following cubes can be made from these nets?
This article outlines the underlying axioms of spherical geometry giving a simple proof that the sum of the angles of a triangle on the surface of a unit sphere is equal to pi plus the area of the triangle.
If the sector is made into a cone by closing up the gap, what
will be the base radius for that cone?
If the cone now suffers a horizontal cut which removes the top
and reduces the height of what remains to half the original cone
height, what curved surface area does that lower shape now
Can you see that an apple can be approximated to a stack of
"headless cones" ?
Not very tall ones!
And you could use that curved surface area calculation you did
earlier to get an approximation for the total apple peel.
Maybe use a spreadsheet to get improved accuracy with more
frustums (the name for headless cones!) ?