Compute the area of...

Riddle me this

Somewhere in the world there must be an exam or test that asks the question to compute the area of a given shape using PL/SQL. I know this because occasionally I look at the Google Analytics for my blog and see some pretty crazy google searches that arrive at my page because of my chosen blog name.

In just a few hours I take off for Hong Kong to take the kids to Disneyland and visit the city for a few days. I'm happy, so (while I don't condone the use of the Internet to solve all your problems) I thought I'd make a few other people happy, and make the visit to my site worthwhile :-)

I've used formulas according to Maths is Fun, and also demonstrated a few other SQL rounding functions you can find well documented here. That's right kids, documentation is your friend.

declare
  lc_pi constant number := 3.141592;
  
  -- triangle
  ln_t_base    number default 2;
  ln_t_height  number default 4;
  
  -- square
  ln_s_length  number default 5;
  
  -- circle
  ln_c_radius  number default 200;
  
  -- ellipse
  ln_e_width   number default 3;
  ln_e_height  number default 2;
  
  -- trapezoid / trapezium
  ln_z_a       number default 2;
  ln_z_b       number default 5;
  ln_z_height  number default 3;
  
  -- sector
  ln_r_radius  number default 4;
  ln_r_degrees number default 45;
  
  ln_area  number;

begin
  -- triangle
  ln_area := 0.5 * ln_t_base * ln_t_height;
  dbms_output.put_line('Triangle: '||ln_area);

  -- square
  ln_area := POWER(ln_s_length, 2);
  dbms_output.put_line('Square: '||ln_area);

  -- circle
  ln_area := lc_pi * POWER(ln_c_radius, 2);

  dbms_output.put_line('Circle: '||ROUND(ln_area, -2));

  -- ellipse
  ln_area := lc_pi * ln_e_width * ln_e_height;
  dbms_output.put_line('Ellipse: '||FLOOR(ln_area));

  -- trapezium
  ln_area := 0.5 * (ln_z_a + ln_z_b) * ln_z_height;
  dbms_output.put_line('Trapezoid: '||CEIL(ln_area));
  
  -- sector
  ln_area := 1/2 * ln_r_radius**2 * ln_r_degrees / 180 / lc_pi;

  dbms_output.put_line('Sector: '||ROUND(ln_area, 5));
  

end simple_calcs;
/  

Triangle: 4
Square: 25
Circle: 125700
Ellipse: 18
Trapezoid: 11
Sector: 6.28319

PL/SQL procedure successfully completed.

See you on the other side of Hong Kong!