Test: Geometry- 2 - Class 4 MCQ

- Tangrams are a type of dissection puzzle consisting of seven flat shapes, known as tans.

- These pieces are typically cut from a square and include:
- 2 large triangles
- 1 medium triangle
- 2 small triangles
- 1 square
- 1 parallelogram
- The objective is to rearrange these pieces to form a specific shape using all seven pieces without overlap.
- The number of geometric shapes in a tangram is seven, making the correct answer B.

A polygon is defined as a closed shape made up of three or more straight lines. Examples of polygons include triangles, quadrilaterals, and pentagons. Understanding polygons is fundamental in geometry, as they form the basis for more complex geometric concepts.

The point where two sides of a polygon meet is called a vertex. Each polygon has a certain number of vertices that correspond to its number of sides. For instance, a triangle has three vertices, while a quadrilateral has four. This concept is essential for analyzing polygon properties.

A circle is not classified as a polygon because it does not consist of straight lines. Polygons must be closed figures formed by straight line segments, while circles are defined by their round shape and lack of corners, showcasing the diversity of geometric forms.

The diameter of a circle is defined as a chord that passes through the center of the circle, effectively dividing it into two equal halves. The diameter is twice the radius, making it a crucial measurement in understanding the properties of circles.

To draw a circle using a piece of thread and a pencil, you can fix one end of the thread to a pin on the paper and attach the pencil to the other end. By holding the thread taut and rotating the pencil around the pin, you create a perfect circle. This method demonstrates the principle of a fixed radius in circle geometry.

The length of the boundary of a circle is called its circumference. The circumference can be calculated using the formula C = 2πr, where r is the radius. Understanding circumference is vital for solving problems related to circular shapes in mathematics.

The diameter of a circle can be calculated as twice the radius. Therefore, if the radius is 4 cm, the diameter is 4 cm × 2 = 8 cm. This relationship between the radius and diameter is fundamental in geometry and is essential for various applications.

The area inside a circle is referred to as the interior of the circle. This area can be calculated using the formula A = πr², where r is the radius. Understanding the interior is important for calculating space and area in geometric problems.

A chord is defined as a line segment that joins any two points on the circumference of the circle. Chords can vary in length, with the longest chord being the diameter. Understanding chords is essential for exploring the properties and relationships within circles.