if the area of the rhombus is 96 cm² and the one diagonal is 4 cm longer than the other, find the two diagonals
Answers
Given :-
- Area of rhombus = 96 cm²
- One diagonal = 4 cm + other diagonal
To find :-
- Two diagonals = ?
Solution :-
Here, let one diagonal be y cm & other diagonal be (y + 4) cm
As we know,
→ Area of rhombus = ½ × d1 × d2
Putting all values
→ 96 cm² = ½ × (y + 4) × y
→ 96 cm² = { y(y + 4) }/2
→ 96 × 2 = y² + 4y
→ 192 = y² + 4y
→ y² + 4y - 192 = 0
→ y² + 16y - 12y - 192 = 0
→ y (y + 16) - 12(y + 16) = 0
→ (y - 12)(y + 16) = 0
→ y = 12 or y = -16
∵ Diagonal of rhombus can't be negative
∴ y = 12 cm
So, one diagonal of rhombus is 12 cm
Finding another diagonal
→ Other diagonal = y + 4
→ Other diagonal = 12 + 4
→ Other diagonal = 16 cm
Therefore,
Two diagonals of rhombus are 16 cm & 12 cm respectively.
QUESTION :
if the area of the rhombus is 96 cm² and the one diagonal is 4 cm longer than the other, find the two diagonals.
SOLUTION :
We know that area of a Rhombus is equal to 1/2 × d1 × d2
Let the length of Diagonal 1 be X cm .
Therefore the length of the other diagonal is X + 4 cm .
=> Area = 1/2 × X × X + 4 = 96
=> X( x + 4 ) = 192
=> X^2 + 4X - 192 = 0
=> X^2 + 16 X -12 X - 192 = 0
=> X ( X + 16 ) - 12 ( X + 16 ) = 0
=> ( X - 12 ) ( X + 16 ) = 0
=> X = 12 cm .
=> Diagonal 1 is 12 cm .
=> Diagonal 2 = X + 4 = 16 cm.
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A n S w E r -
The lengths of the two diagonals are 12 cm and 16 cm respectively..