Question

A rhombus has all internal angles equal ,if one of the diagonal is 15 cm find the length of the other diagonal and find the area of the rhombus

Answer 1

Let angles be x
so given
$x + x + x + x = 360$
by angle sum property
$4x = 360 \\ x = 360 \div 4 \\ x = 90$
since all angles are 90° and all sides are equal in rhombus, so it means the figure is a square.
In a square both diagonals are equal, so area =
$\frac{1}{2} \times 15 \times 15 \\ = \frac{225}{2} = 114.5$
hope it helps