1.
What shape is a 3d circle?
Correct Answer
D. Sphere
Explanation
A 3D circle does not exist as a shape. A circle is a 2D shape, so it only has two dimensions - length and width. A sphere, on the other hand, is a 3D shape that has three dimensions - length, width, and height. Therefore, a sphere is the closest shape to a 3D circle because it is a round object in three dimensions.
2.
What shape is the cross-section of the sphere?
Correct Answer
B. Circle
Explanation
The cross-section of a sphere is always a circle. A sphere is a three-dimensional object with all points on its surface equidistant from its center. When a plane intersects a sphere, the resulting cross-section is a circle. This is because a circle is a two-dimensional shape with all points equidistant from its center, just like the surface of a sphere. Therefore, the correct answer is circle.
3.
What kind of shape will you get with a cross-section parallel to the base?
Correct Answer
B. Circle
Explanation
A cross-section parallel to the base of a cylinder will result in a circle. This is because a cylinder has a circular base, and any cross-section that is parallel to the base will have the same shape as the base, which is a circle.
4.
Will the cross-section be congruent to the base of a cylinder.
Correct Answer
A. No
Explanation
The cross-section of a cylinder is a circle, while the base of a cylinder is also a circle. Since the question asks if the cross-section will be congruent to the base, and the answer is "no," it implies that the cross-section is not a circle and therefore not congruent to the base.
5.
What is a description of a cone?
Correct Answer
B. A figure with a pointed top and a circled bottom
Explanation
A cone is a three-dimensional geometric shape that has a pointed top and a circular base. The pointed top is called the apex, and the circular base is the bottom of the cone. The shape of a cone resembles that of an ice cream cone or a traffic cone.
6.
A 3-D shape can also be called...
Correct Answer
B. A solid shape
Explanation
A 3-D shape can also be called a solid shape because it has three dimensions - length, width, and height. Unlike flat shapes, which only have two dimensions, solid shapes have volume and take up space in three-dimensional space. Solid shapes can be seen and touched from different angles, and they have depth. Therefore, the term "solid shape" accurately describes a 3-D shape.
7.
Vertices are also called...
Correct Answer
B. Corners
Explanation
Vertices are points where two or more edges meet in a geometric shape. In two-dimensional shapes, such as polygons, vertices are commonly referred to as corners. Therefore, the correct answer is "Corners".
8.
A solid object has six faces which are all squares. What is the name of this object?
Correct Answer
A. Cube
Explanation
A cube is a solid object that has six faces, all of which are squares. Therefore, the correct answer is Cube.
9.
Which 3-D shape has six rectangular faces?
Correct Answer
B. Cuboid
Explanation
A cuboid is a 3-D shape that has six rectangular faces. It is similar to a rectangular prism, with opposite faces being equal in size and shape. The rectangular faces of a cuboid make it different from other shapes like a sphere, cylinder, or square, which do not have six rectangular faces. Therefore, the correct answer is cuboid.
10.
Most dice are the shape of which 3-D shape?
Correct Answer
C. Cube
Explanation
A cube is a three-dimensional shape with six equal square faces. Most dice are shaped like cubes, with each face having a different number of dots or pips. This shape allows for equal probability of landing on any face when rolled, making it ideal for games of chance.