Question

figure | cross section
(a) image of a triangular prism with a blue plane | shapes: crescent, triangle, hexagon, circle, pentagon, rectangle with radio buttons
(b) image of a cone with a blue plane | shapes: trapezoid, triangle, hexagon, circle, pentagon, rectangle with radio buttons
(c) image of a cylinder with a blue plane | shapes: trapezoid, triangle, hexagon, circle, pentagon, rectangle with radio buttons
explanation check

Explanation:

Step1: Analyze Figure (a)

The figure (a) is a triangular prism. A cross - section parallel to the lateral faces (or cutting through the prism in a way that is perpendicular to the triangular bases) will result in a triangle? Wait, no. Wait, the triangular prism has two triangular bases and three rectangular lateral faces. If we cut the triangular prism with a plane that is parallel to the lateral faces (the rectangles), actually, when we look at the plane cutting the triangular prism as shown, the cross - section should be a triangle? Wait, no, let's re - examine. The triangular prism: the base is a triangle. If we cut the prism with a plane that passes through the three edges (one from each lateral face) in a way that is parallel to the triangular base, the cross - section is a triangle. Wait, the second cross - section option is a triangle. Wait, no, the figure (a) is a triangular prism. The plane is cutting through the prism, and the cross - section should be a triangle? Wait, no, the first figure (a) is a triangular prism. The cross - section when cut by a plane that is parallel to the triangular base (the front - facing triangle) will be a triangle. So for (a), the correct cross - section is the triangle (the second option).

Step2: Analyze Figure (b)

Figure (b) is a cone. When we cut a cone with a plane that passes through the vertex and is perpendicular to the base (a vertical plane through the axis of the cone), the cross - section is a triangle. So for (b), the correct cross - section is the triangle (the second option).

Step3: Analyze Figure (c)

Figure (c) is a cylinder. When we cut a cylinder with a plane that is parallel to the bases (the circular bases), the cross - section is a circle. So for (c), the correct cross - section is the circle (the fourth option).

Answer:

For (a): The second cross - section (the triangle).
For (b): The second cross - section (the triangle).
For (c): The fourth cross - section (the circle).