SAT Question ca2235f6: Circles answer and explanation with Desmos solution

Choice D is correct. It's given that the measure of arc $AB$ is $45^{\circ }$ and the length of arc $AB$ is $3$ inches . The arc measure of the full circle is $360^{\circ }$. If $x$ represents the circumference, in inches, of the circle, it follows that $\frac{45^{\circ }}{360^{\circ }}=\frac{3\text{inches}}{x\text{inches}}$. This equation is equivalent to $\frac{45}{360}=\frac{3}{x}$, or $\frac{1}{8}=\frac{3}{x}$. Multiplying both sides of this equation by $8x$ yields $1(x)=3(8)$, or $x=24$. Therefore, the circumference of the circle is $24$ inches .