Question

The side of rhombus is 10 cm and one of its diagonal is 12 cm. Find it's perimeter and area.​

Answer 1

Answer:

perimeter is....10+10+10+10..

=40.

area ni pata......

Answer 2

$perimeter(rhombus) \\ = 4 \times side \\ = 4 \times 10 \\ = 40 \: cm$

now, since diagonals of a rhombus are perpendicular bisectors of each other

OB = OD

BD = 12 cm

OB = OD = 6 cm

In ∆AOB, angle AOB = 90°

AB = 10 cm

OB = 6 cm

using Pythagoras Theorem, we get,

OA = 8 cm = OC

AC = 16 cm

$area(rhombus) \\ = \frac{1}{2} \times d_{1} \times d_{2} \\ = \frac{1}{2} \times 6 \times 8 \\ = \frac{1}{2} \times 48 \\ = 24 \: {cm}^{2}$