<span>A cross section is formed by the <em>intersection</em> of a<em> three-dimensional object</em> and a <em>plane.</em>
So the right answers are 4 and 5.
Let's explain each case.
First. A prism and a horizontal plane
The representation of this statement is shown in Figure 1. A prism has the following characteristics:
1. These objects have identical ends.
2. They have flat faces.
3. They have </span><span>the same </span>cross section<span> all along its length </span><span>
So in the figure, you can see how the horizontal plane intersects the prism. <em>The cross section</em> of this object <em>is a</em> <em>triangle</em>. Thus, </span><span>it has the same cross section all along its length and this object is called <em>a triangular prism.</em></span><span>
Second. A vertical plane and a pyramid
As shown in Figure 2 you can see the representation of this statement. </span><span>If the pyramid is cut with a plane that passes through the top vertex and it is perpendicular to the base, then the intersection of this pyramid and the plane becomes a <em>triangular cross section</em>.</span>
So the right answers are 4 and 5.
Let's explain each case.
First. A prism and a horizontal plane
The representation of this statement is shown in Figure 1. A prism has the following characteristics:
1. These objects have identical ends.
2. They have flat faces.
3. They have </span><span>the same </span>cross section<span> all along its length </span><span>
So in the figure, you can see how the horizontal plane intersects the prism. <em>The cross section</em> of this object <em>is a</em> <em>triangle</em>. Thus, </span><span>it has the same cross section all along its length and this object is called <em>a triangular prism.</em></span><span>
Second. A vertical plane and a pyramid
As shown in Figure 2 you can see the representation of this statement. </span><span>If the pyramid is cut with a plane that passes through the top vertex and it is perpendicular to the base, then the intersection of this pyramid and the plane becomes a <em>triangular cross section</em>.</span>