The lengths of two sides of a parallelogram are 3 cm and 10 cm. What is the half of the sum of the squares of the diagonals of the parallelogram?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 109 cm2.
Sum of square of diagonals of parallelogram = 2(a2 + b2) where a and b are the sides of the parallelogram.
Sides of Parallelogram = 3cm and 10cm
According to question
Sum of square of diagonals of parallelogram = 2(a2 + b2)
Putting the values, we get
The sum of square of diagonals of parallelogram = 2(32 + 102)
⇒ 2(9 + 100) = 218 cm
It's half = 218/2 = 109 cm