No me han dicho que me ha dicho nada de la policía y que han
Find the length of AB
AB²=20²+15²
AB²=400+225
AB²=625
AB=25
then find AD and BD
20²=AD·25
400=AD·25
AD=16
15²=BD·25
225=BD·25
BD=9
now use the geometric mean theorem (name?) to find CD
CD=√(9·16)
CD=√144
CD=12 cm
In order to find the value of x, we need to remember that the sum of the interior angles of a triangle is 180°
so we have the next equation
21+x+(180-133)=180
21+x+47=180
x=180-21-47
x=112°