2d Shapes

What is the perimeter of a square with side length 5 cm?

• 15 cm

• 20 cm

• 25 cm

• 30 cm

Answer explanation

The perimeter of a square is calculated by multiplying the side length by 4. For a square with a side length of 5 cm, the perimeter is 5 cm x 4 = 20 cm. Therefore, the correct answer is 20 cm.

What is the formula for calculating the area of a rectangle?

• 2(length + width)

• length x width

• length - width

• length + width

Answer explanation

The area of a rectangle is calculated by multiplying its length by its width. Therefore, the correct formula is 'length x width', which represents the total space within the rectangle.

Which of the following shapes is a three-sided polygon?

• Square

• Circle

• Triangle

• Rectangle

Answer explanation

A triangle is a three-sided polygon, defined by three edges and three vertices. In contrast, a square and rectangle have four sides, and a circle has no sides, making triangle the correct choice.

What is the distance from the center to the outer line of a circle called?

• Perimeter

• Diameter

• Circumference

• Radius

Answer explanation

The distance from the center to the outer line of a circle is called the radius. It is half the diameter and is essential for calculating the area and circumference of the circle.

How do you calculate the perimeter of a triangle?

• length x width

• s x 3

• a + b + c

• 2(a + b)

Answer explanation

To calculate the perimeter of a triangle, you add the lengths of all three sides. The correct formula is a + b + c, where a, b, and c are the lengths of the sides.

What is the area of a square with side length 5 cm?

• 20 cm²

• 35 cm²

• 25 cm²

• 30 cm²

Answer explanation

The area of a square is calculated by squaring the side length. Here, the side length is 5 cm. Thus, the area = 5 cm × 5 cm = 25 cm². Therefore, the correct answer is 25 cm².

Which of the following is NOT a common 2D shape?

• Triangle

• Circle

• Square

• Cube

Answer explanation

A cube is a 3D shape, while a triangle, circle, and square are all common 2D shapes. Therefore, the correct answer is cube, as it does not belong to the category of 2D shapes.

What is the formula for the perimeter of a rectangle?

• s x 4

• 2(length + width)

• length x width

• length + width

Answer explanation

The perimeter of a rectangle is calculated by adding the lengths of all sides. The formula is 2(length + width), which accounts for both pairs of opposite sides.

What is the area of a rectangle with length 6 cm and width 4 cm?

• 24 cm²

• 30 cm²

• 20 cm²

• 36 cm²

Answer explanation

The area of a rectangle is calculated by multiplying the length by the width. Here, 6 cm (length) × 4 cm (width) = 24 cm². Therefore, the correct answer is 24 cm².

What is the term for a shape that has length and width but no height?

• 3D shape

• 2D shape

• Cuboid

• Sphere

Answer explanation

A shape with length and width but no height is called a 2D shape. Unlike 3D shapes, which have depth, 2D shapes exist only in two dimensions, making '2D shape' the correct answer.