Step-by-step explanation:
soln:
In right-angled triangle,
hypotenuse (h)=20mm
base(b)=12mm
perpendicular (p)=?
Now,using Pythagoras theorem,
h^2=p^2+b^2
or, 20^2=p^2+12^2
or,400-144=p^2
or,p=√256
thus,p=16mm
Now,
perimeter= sum of all three sides
i.e. p=20+12+16=48 Ans
