Explanation

A sphere is a 3D (three-dimensional) shape because it has depth, along with height and width.

Circle, rectangle, and triangle are 2D (two-dimensional) shapes as they have only length and width.

Explanation

To find the length of marks on dust when the wheel completes one rotation, we need to calculate the circumference of the wheel:

Circumference = π × diameter

= π × 35 cm

≈ 3.14 × 35 cm

≈ 109.9 cm

Rounding to the nearest whole number:

≈ 110 cm

Explanation

The angle sum of a triangle will always be equal to 180°.

The angle sum of a quadrilateral is equal to 360°

And a triangle can be created by slicing a quadrilateral in half from corner to corner. Since a triangle is essentially half of a quadrilateral

Its angle measures should be half as well. Half of 360° is 180°

Explanation

The area of a trapezium is given by:

Area = (1/2) × (sum of bases) × altitude

Given:

Area = 153 m^2

Altitude = 9 m

One base = 13 m

Let's denote the other base as 'b'. Then:

153 = (1/2) × (13 + b) × 9

Multiply both sides by 2:

306 = (13 + b) × 9

Divide both sides by 9:

34 = 13 + b

Subtract 13 from both sides:

b = 21

Explanation

A square has four equal angles, and each angle measures 90 degrees.

It’s a property of all regular quadrilaterals.