Question

11. The length of a side of a rhombus is 4.1 cm and one of its diagonals is 1.8 cm.
Find the area of the rhombus.
(2018) 1
(1) 10.8 sq cm (2) 3.6 sq cm (3) 7.2 sq cm (4) 8.1 sq cm​

Answer 1

Answer:

the correct answer is (3) 7.3 sq cm

Step-by-step explanation:

area of triangle=

s=(4.1+4.1+1.8)/2 =10/2, =5cm

\sqrt{5(5 - 4.1)(5 - 4.1)(5 - 1.8)}

5(5−4.1)(5−4.1)(5−1.8)

=

\sqrt{5 \times .9 \times .9 \times 3.2}

5×.9×.9×3.2

=4×0.9 , =3.6 cm^2

area of rhombus=2×3.6, =7.2 cm^2