Question
he perimeter of a rhombus is 146 cm. One of its diagonals is 55 cm. Find the length of the other diagonal and area of the rhombus.
Solution
Length of a side of the rhombus




For ΔABC
a = 36.5 cm b = 55 cm c = 36.5 cm
Area of the ΔABC
∴ Area of the rhombus ABCD
= 2 Area of the ΔABC = 2 x 660 = 1320 cm2
∴ Length of the other diagonal is 48 cm.