Question

the length of the diagnal of a square is 20 cm. its area is

Answer 1

diagonal(d)=20cm

area of square=d^(square)÷2
=20^2÷2
=400÷2
=200cm^2
i hope this ans will help u

Answer 2

diagonal of square =√2a,where a is the length of side of square.                               here √2a=20,∴a=10√2                                                                                                    and area of square =a²=(10√2)²=200 cm²