Q:

Draw the Ionising Radiation Hazard Symbol

Draw the ionising-radiation-hazard-symbol in an arbitrary colour on a distinctly coloured background. The specific proportions were published in the June 27th 1974 issue of the Federal Register of the US Government.
Details

As output, writing to a file (raster and vector formats are permitted) or displaying on the screen are both allowed.
You can draw just the border or the filled shape.
If you use raster images, you should take a parameter (or two) as input that lets you adjust the resolution of the output (e.g. width/height).
The background must at least have the size of the bounding box of the symbol but may be larger.
Outputting the unicode symbol ☢ is not sufficient.
The exact ratios of the used distances are given in following diagram (which was originally from here):

Related: Draw the ☣ (Biohazard Symbol)

A:

BBC BASIC, 200 bytes
f=500
g=1/SQR(3)
CIRCLE FILLf,f,f
GCOL15
MOVE-100,f
MOVEf,f
PLOT85,f*(1-g),0
MOVE1100,f
MOVEf,f
PLOT85,f*(1+g),0
MOVEf*(1-g),2*f
MOVEf,f
PLOT85,f*(1+g),2*f
CIRCLE FILLf,f,150
GCOL0
CIRCLE FILLf,f,100

Somehow outgolfing Python, this works by drawing a large black circle, filling in the white triangular sections, drawing a central white circle and finally drawing the central black circle.

A:

MATL, 46 44 41 bytes
:t_0vSt!Yy1MZ;3*YP/koyG.3*>*yG<*wG5/<=3YG

Given an input n, the image has width 2*n+1 in pixels.
Try it at MATL Online!
Explanation
:       % Implicit input n. Range [1 ... n]
t_      % Duplicate, negate. Gives [-1 ... -n]
0       % Push 0
v       % Concatenate stack as a column vector: [1; ...; n; -1; ...; -n; 0]
S       % Sort. Gives [-n; -n+1; ... n]
t!      % Duplicate, transpose. Gives the row vector [-n -n+1 ... n]
Yy      % Hypotenuse, with implicit expansion. Gives a matrix containing radius
        % for all points in a grid from -n to -n
1M      % Push the two inputs of the last function, again
Z;      % atan2, with implicit expansion. Gives a matrix containing angle between
        % -pi and pi, where 0 is real positive semiaxis
3*YP/k  % Multiply by 3, divide by pi, round down. Gives an integer for each sextant
o       % Parity. This assigns 0 and 1 alternately to points in different sextants.
        % See this partial result as IMAGE 1 below.
y       % Duplicate from below: pushes the matrix of radii again
G.3*>   % Greater than 0.3*n?, element-wise. Gives 0 or 1 for each entry. This
        % realizes the "1.5R" circle from the specification. See IMAGE 2
*       % Multiply, element-wise. See IMAGE 3
y       % Duplicate from below: pushes the matrix of radii again
G<      % Less than n?, element-wise. Gives 0 or 1 for each entry. This realizes
        % the "5R" circle from the specification. See IMAGE 4
*       % Multiply, element-wise. See IMAGE 5
w       % Swap: pushes the original matrix of radii to the top
G5/<    % Mess than 0.2*n? This realizes the "R" circle in the spec. See IMAGE 6
=       % Equal?, element-wise. This combines the two matrices so far to produce
        % the final result, with 0 for foreground pixels and 1 for background pixels.
        % See IMAGE 7
3YG     % Show image. 0 is displayed as black, 1 as white

Intermediate results. 0 is shown as black, 1 as white: 

Image 1:

Image 2:

Image 3:

Image 4:

Image 5:

Image 6:

Image 7 (final result):

A:

SVG(HTML5), 175 bytes

<svg viewBox=-24,-24,48,48><circle r=4 /><path id=b d=M3,-5.2A6,6,0,0,1,6,0H20A20,20,0,0,0,10,-17.32z /><use href=#b transform=rotate(120) /><use href=#b transform=rotate(240)

Originally based on @Arnauld's answer, but removes unnecessary characters, scales the numbers by 80% to make them golfier, and draws the curved section's lines in a different order so that I can use an H instead of an L.

