The glass prism
Two triangles, three rectangles.
A triangular block of glass
Glass blocks come in many shapes. One has triangles at its ends and flat rectangles along its sides.
What is the shape of the ends of such a block?
What this lesson covers
The idea
A triangular glass prism has two triangular bases and three rectangular lateral surfaces inclined to each other; the angle between two of its lateral faces is the angle of the prism.
A triangular block of glass
Glass blocks come in many shapes. One has triangles at its ends and flat rectangles along its sides.
What is the shape of the ends of such a block?
- Triangular
- Rectangular
- Circular
Look at the prism
Press Next step.
Parts of a prism
A triangular glass prism has two triangular bases at its ends and three rectangular lateral surfaces. The lateral surfaces slope towards one another. The angle between two of them is the angle of the prism.
A triangular glass prism has two triangular bases and three rectangular lateral surfaces inclined to each other. The angle between two of its lateral faces is the angle of the prism.
Notes
A triangular glass prism has two triangular bases and three rectangular lateral surfaces inclined to each other; the angle between two lateral faces is the angle of the prism.
Check yourself
How many triangular bases does a triangular glass prism have?
Answer: 2
It has two triangular bases and three rectangular lateral surfaces.
How many rectangular lateral surfaces does a triangular glass prism have?
Answer: 3
It has three rectangular lateral surfaces.
The angle of the prism is the angle between…
The lateral surfaces of a prism are…
- its two triangular bases. The angle of the prism is the angle between two of the lateral faces.
- two of its lateral faces — correct. Yes!
- the incident ray and the emergent ray. That is the angle of deviation, not the angle of the prism.
- parallel to each other. The refracting surfaces of a glass slab are parallel. The lateral surfaces of a prism are inclined to each other.
- triangular in shape. The lateral surfaces are rectangular. The bases are triangular.
- inclined to each other — correct. Yes!