Step 1.

Make a frog base and hold it vertically in your hand.

additional information

  • The shape could be described as a four-faced polyhedron.
  • Each face is a vertical diamond, with the small diagonal (horizontal) acting as a hinge fold connecting a small double-thickness triangular flap with the free tip pointing upward.
  • The lower part of the vertical diagonal is a slit that divides the lower part of the diamond into two triangles.
  • The right and left faces are folded onto themselves along the vertical axis.

Step 2.

Place your thumbs on the small triangular flap in the middle of the front face.

Place your middle fingers on the small triangular flap in the middle of the back face.

Right index finger at the top of the small triangle between the two right flaps.

Left index finger at the top of the small triangle between the two left flaps.

Step 3.

Push down the small triangles on the right and left sides.

Step 4.

Rotate the shape a quarter turn clockwise.

additional information

  • The front side has become the left side and the back side has become the right side.
  • The front and back sides are folded in on themselves, unlike the right and left sides.

Step 5.

Hold the bottom right points between the thumb and index finger of your right hand.

Hold the bottom left points between the thumb and index finger of your left hand.

Step 6.

Slightly spread your hands until the right and left points are flat and horizontal on the table.

additional information

  • This operation causes the front and back faces of the shape to unfold.
  • Under your left hand, side by side, are two tapered quadruple-thickness triangles pointing to the left; a valley hinge fold connects them to a small triangular flap pointing upwards.
  • Under your right hand, side by side, are two tapered quadruple-thickness triangles pointing to the right; a valley hinge fold connects them to a small triangular flap pointing upwards.
  • Between the two small vertical triangular flaps is a square-based pyramid whose front, left, back, and right faces are four triangles meeting to form the top of the pyramid.

Step 7.

Place your index fingers between the base of the pyramid and the small vertical triangular flaps.

Step 8.

Move the left index finger to the right and the right index finger to the left to force the front and back faces of the pyramid to fold.

additional information

  • The pyramid becomes a thick triangular flap, equidistant from the two small triangular flaps.

Step 9.

Rotate the three vertical flaps horizontally (to the left).

additional information

  • The base of the stretched frog is complete.