question_answer

If one side and one diagonal of a rhombus are 13 cm and 10 cm, its area in sq. cm. is :

A) 240

B) 200

C) 120

D) 140

E) None of these

Correct Answer: C

Solution :

Explanation Option (c) is correct. AB = 13 cm, BD = 10 cm \[OB=\frac{10}{2}=5\,\,cm\] \[\therefore \]      AO = \[\sqrt{169-25}\]                         = 12 cm             \[\therefore \]      AC = 24 cm             \[\therefore \]      Area of rhombus             \[=\frac{1}{2}\times (24\times 10)=120\,\,sq.\,\,cm.\]