Chapter 13.9, Problem 1AE

To determine

To measure the angles where the soap film meet.

Answer to Problem 1AE

The angle between any two tangent planes to the intersecting surfaces, at any point along the line of intersection of three surfaces, is ${120}^0$

Explanation of Solution

Given information: 

The model is dipped in Soap Solution that minimises the surface area.

Concept used:

Three smooth surfaces of a soap film intersect along a line.

Explanation: 

  

After taking out the model from soap solution we will obtain 3-D figure as shown above.

By placing the protector on top of the model where soap films meet, measure the angles.

The angle between any two tangent planes to the intersecting surfaces, at any point along the line of intersection of three surfaces, is ${120}^0$