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The diagonals of a rhombus are 7 cm and 24 cm. Find the perimeter of the rhombus.
50 cm
25 cm
30 cm
40 cm
50 cm
Given: Diagonals of the rhombus: d₁ = 7 cm and d₂ = 24 cm.
Diagonals of the rhombus: d₁ = 7 cm and d₂ = 24 cm.
Side (a)=21d1°2+d2°2,Perimeter (P)=4a
Use the Pythagorean triplet for half-diagonals: half of 7 is 3.5 and half of 24 is 12. Triplet (3.5, 12, 12.5) gives side = 12.5 cm. Perimeter = 4 × 12.5 = 50 cm.
Confusing side length with perimeter and stopping at 12.5 cm, or directly calculating 4 × 72+242 without dividing the diagonals by 2.
Identify Given Properties of Rhombus
Let the lengths of the diagonals of the rhombus be d1=7 cm and d2=24 cm. In a rhombus, diagonals bisect each other at right angles (90°).
d1=7 cm,d2=24 cm
Calculate the Length of Side of Rhombus
Using the relationship between the side a and diagonals d1,d2 derived from Pythagoras theorem: a=(2d1)2+(2d2)2=21d1°2+d2°2.
a=217°2+24°2=2149+576=21625=225=12.5 cm
Calculate the Perimeter
Since all four sides of a rhombus are equal, the perimeter P is given by P=4a.
P=4×12.5=50 cm
A is correct because calculating side a=12.5 cm yields a total perimeter of P=4×12.5=50 cm.
Direct formula for perimeter of a rhombus in terms of diagonals: P=2d1°2+d2°2. This saves time by avoiding decimals like 3.5 in competitive exams.