Question

find the area of equilateral triangle whose side is 3cm​

Answer 1

Answer:

Area of the triangle is 3.9

Answer 2

$\blue{\bold{\underline{\underline{Answer:}}}}$

$\green{\therefore{\text{Area\:of\:triangle=3.9\:cm}^{2}}}$

$\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}$

$\green{ \underline \bold{Given : }} \\ : \implies \text{Sides \: of \: triangle =3 cm,3 cm,3 cm} \\ \\ \red{ \underline \bold{To \: Find : }} \\ : \implies \text{Area \: of \: triangle = ?}$

• According to given question :

$\bold{As \: we \: know \: that \: herons \: formula} \\ : \implies s = \frac{a + b + c}{2} \\ \\ : \implies s = \frac{3+3+ 3}{2} \\ \\ : \implies s = \frac{9}{2} \\ \\ \green{ : \implies s =4.5 } \\ \\ \circ\: \bold{Area \: of \: triangle = \sqrt{s(s - a)(s - b)(s - c)} } \\ \\ : \implies \text{Area \: of \: triangle =} \sqrt{4.5(4.5- 3)(4.5-3)(4.5- 3)} \\ \\ : \implies \text{Area \: of \: triangle =}\sqrt{4.5\times 1.5\times 1.5\times 1.5} \\ \\ : \implies \text{Area \: of \: triangle =} \sqrt{15.1875} \\ \\ : \implies \text{Area \: of \: triangle =}3.9\: cm^{2} \\ \\ \ \green{\therefore \text{Area \: of \: triangle = 3.9\: {cm}}^{2} }$

$\bold{Another \: method} \\ : \implies \text{Area \: of \: equilateral \: triangle =} \frac{ \sqrt{3} }{4} {side}^{2} \\ \\ : \implies \text{Area \: of \: equilateral \: triangle =} \frac{ \sqrt{3} }{4} \times {3}^{2} \\ \\ : \implies \text{Area \: of \: equilateral \: triangle =} \frac{ \sqrt{3} \times 9}{4} \\ \\ : \implies \text{Area \: of \: equilateral \: triangle =} {1.732 \times 2.25} \\ \\ \green{: \implies \text{Area \: of \: equilateral \: triangle =}3.9 {cm}^{2} }$