Respuesta :

9 m

Step-by-step explanation:

The formula is a^2+b^2=c^2

If...

a = 12 m

c = 15 m

Then,

a^2+b^2=c^2

144+b^2=225

b^2=225-144

b^2=81

b=9

Length is 9 m.

It has been given that

its width is 12 metres

and its diagonal is 15 metres

So by Pythagoras theorem we

get length to be 13 metres

Hope it helps♥️❤️