Hint: Here in this question, we have to find the circumference of a circle. The circumference of a circle is defined as the outer region of a circle. It is given as \[C = 2\pi r\]. On substituting the values to the formula, we obtain the required result to the above question.
Complete step-by-step solution: A circle is a shape consisting of all points in a plane that are a given distance from a given point or centre; equivalently it is the curve traced out by a point that moves in a plane so that its distance from a given point is constant. The Radius is the distance from the centre to outwards. The Diameter goes straight across the circle, through the centre of a circle. The Circumference is the distance once around the circle. The formula for the circumference is given by \[C = 2\pi r\], where C is the circumference and r is the radius of a circle. As in the question they have mentioned diameter. The radius of a circle is not given. By the definition of diameter, we know that the diameter is twice of a radius. Therefore d = 2r. Therefore the formula is written as \[ \Rightarrow C = 2r\pi \] \[ \Rightarrow C = d\pi \] Where d = 7.5 in, on substituting the value of d we have \[ \Rightarrow C = 7.5 \times \pi \] As we know that the value of \[\pi = 3.14\] On substituting we get \[ \Rightarrow C = 7.5 \times 3.14\] \[ \Rightarrow C = 23.55in\] Therefore the circumference of a circle with a radius 7.5 in is 23.55 in.
Note: While finding area or circumference the unit must and should be mentioned in the final answer. Suppose if we don’t mention the unit then there is no value for the result at all. The unit for the circumference will remain the same as the unit mentioned for the radius or diameter. But the unit for the square is included.