Red five-pointed star

Apply sine law on the figure on the right.

$\dfrac{x}{\sin 36}=\dfrac{10}{\sin 126}$ $\implies$ $x=10\left(\dfrac{\sin 36}{\sin 126}\right) \approx 7.265$

The area of the star is equal to the area of this triangle multiplied by 10 (since there are 10 triangles). So the area of the star is $\dfrac{1}{2}(10)(7.265)(\sin 18)(10) \approx 112.25$ .

The area of the yellow region is equal to the area of the circle minus the area of the star. We have

$A=\pi (10)^2 - 112.25 \approx \color{#69047E}\boxed{202}$