Question

Find the area of an equilateral triangle whose each side is 40cm

Answer 1

Answer:

Step-by-step explanation:

to find the area of equilateral triangle ,

the formula is  √3/4 a²

   => given side = 40 cm

  => let a = 40 cm

   => √3/4 × 40²

=> 692.82 cm²

===========================================================

  hope it will be the answer

tQ

Answer 2

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

$\green{\therefore{\text{Area\:of\:triangle=692.82\:cm}^{2}}}$

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

$\green{ \underline \bold{Given : }} \\ : \implies \text{Sides \: of \: triangle =40 cm,40 cm,40 cm} \\ \\ \red{ \underline \bold{To \: Find : }} \\ : \implies \text{Area \: of \: triangle = ?}$

• According to given question :

$\bold{As \: we \: know \: that \: herons \: formula} \\ : \implies s = \frac{a + b + c}{2} \\ \\ : \implies s = \frac{40+40+40}{2} \\ \\ : \implies s = \frac{120}{2} \\ \\ \green{ : \implies s =60 } \\ \\ \circ\: \bold{Area \: of \: triangle = \sqrt{s(s - a)(s - b)(s - c)} } \\ \\ : \implies \text{Area \: of \: triangle =} \sqrt{60(60- 40)(60-40)(60- 40)} \\ \\ : \implies \text{Area \: of \: triangle =}\sqrt{60\times 20\times 20\times 20} \\ \\ : \implies \text{Area \: of \: triangle =} \sqrt{480000} \\ \\ : \implies \text{Area \: of \: triangle =}692.82\: cm^{2} \\ \\ \ \green{\therefore \text{Area \: of \: triangle =692.82\: {cm}}^{2} }$

$\bold{Another \: method} \\ : \implies \text{Area \: of \: equilateral \: triangle =} \frac{ \sqrt{3} }{4} {side}^{2} \\ \\ : \implies \text{Area \: of \: equilateral \: triangle =} \frac{ \sqrt{3} }{4} \times {40}^{2} \\ \\ : \implies \text{Area \: of \: equilateral \: triangle =} \frac{ \sqrt{3} \times 1600}{4} \\ \\ : \implies \text{Area \: of \: equilateral \: triangle =} {1.732 \times 400} \\ \\ \green{: \implies \text{Area \: of \: equilateral \: triangle =}692.82 {cm}^{2} }$