Respuesta :
Answer:
≈ 43.3 cm²
Step-by-step explanation:
The area (A) of an equilateral triangle is calculated as
A = [tex]\frac{s^2\sqrt{3} }{4}[/tex] ( s is the side length )
The 3 sides of an equilateral triangle are congruent, thus
s = 30 ÷ 3 = 10 cm
A = [tex]\frac{10^2\sqrt{3} }{4}[/tex] = [tex]\frac{100\sqrt{3} }{4}[/tex] = 25[tex]\sqrt{3}[/tex] ≈ 43.3 cm²
Answer:
43.30cm²
Step-by-step explanation:
Use Herons formula
S = (a+b+c)÷2
Where a, b, c is the sides of the triangle
If perimeter is 30cm
Since it's an equilateral triangle, all sides are equal.
Then
Perimeter = 3a = 30
a = 30/3 = 10cm
b = 10cm , c = 10cm
Therefore ,s= (10+10+10)÷2 = 30÷2 = 15cm
From Herons formula
Area = square root of s(s-a)(s-b) (s - c)
Area = sq rt 15(15 - 10)(15 - 10)(15 - 10)
Area = sq rt 15.× 5 × 5 ×5
Area = sq rt 1875
Area = 43.30cm²
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