Question

Area of a rhombus is equal to one-half of the product of the lengths of___

Answer 1

ABCD is a rhombus. Now in a rhombus, the diagonals bisect each other perpendicularly.
Hence, area of rhombus = Area of triangle ABC + Area of triangle ADC
$=\frac{1}{2}\times AC\times \left(\frac{1}{2}\right)\times \left(AC\right)\times \left(\frac{BD}{2}\right)=\frac{1}{2}\times AC\times BD$
which is one half of the product of the lengths of the diagonals.