Area of an equilateral triangle is 25*sqrt3 cm^2. Perimeter is

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07 May 2013 Triangle

Area of an equilateral triangle is 25*sqrt3 cm^2. Perimeter is

OPtion

1) 10 cm
2) 20 cm
3) 30 cm
4) 40 cm
5) 10*sqrt3 cm
6) 20*sqrt3 cm
7) 30*sqrt3 cm
8) 40*sqrt3 cm
9) 50 cm
10) None of these

Solution

(sqrt3/4)*a^2=25*sqrt3 (let a be the side of an equilateral triangle)
a^2=100
a=10
perimeter 30cm
option 3

Correct Option: 3 Best Solution (17)

Devendra Marghade   11 years AGO

If a= side of an equilateral triangle then
Area of the triangle=Sqrt3*a^2/4=25*sqrt3
a^2=100 or a=10
So perimeter=3a=3*10=30 cm.

Like? Yes (3) | No   

navneet   11 years AGO

area of equilateral triangle = sqrt3/4 * a^2
a- side of the triangle
sqrt3/4 * a^2 = 25sqrt3
a^2 = 25sqrt3*4/sqrt3
a^2 = 25*4
a = 5*2 = 10
perimeter of equilateral triangle = 3a
3*10 = 30 cm.

Like? Yes (4) | No (1)  

jitendra singh   11 years AGO

30

Like? Yes (3) | No   

AVINASH KUMAR   11 years AGO

Area of an equilateral triangle is eqals to
=(srt3/4)*side^2= 25*sqrt3 cm^2
=>side^2=100cm^2
=>side=10cm
Perimeter of an equilateral triangle is 3*side=3*10=30cm

Like? Yes (2) | No   

Satyaranjan   11 years AGO

Area=[(sqrt3)/4]side^2=25*sqrt3 cm^2
=>Side=sqrt100=10cm
=>Perimeter=3*Side=30cm

Like? Yes (1) | No   

Suranjan   11 years AGO

Area=(sqrt3/4)a.a=25sqrt3
=>a=10
=>3a=perimeter=30cm

Like? Yes (1) | No   

krishnapriya   11 years AGO

Area of an equilateral triangle=bh/2
By pythagoras theroem,
h^2+x^2=(2x)^2
(ie)h=xsqrt3
therefore, Area=sqrt3*x^2
(ie)25*sqrt3=sqrt3*x^2
x=5cm
perimeter=2x+2x+2x=6x=6*5=30cm

Like? Yes (1) | No   

Shalu Jain   11 years AGO

area of a equilateral triangle =(a^2*sqrt3)/4
a=side of the triangle
a=10
perimeter=30

Like? Yes (1) | No   

Deepak   11 years AGO

let side be a,
Sqrt3/4*square a=25*sqrt3,
solving a=10,3a=30 cm

Like? Yes (1) | No   

Dr.Dipin Singh   11 years AGO

A= s^2 x ( square root (3))/4 = 25*sqrt3 cm^2
s^2=100
s=10
perimeter= 3*s=3*10=30 cms

Like? Yes (1) | No   

Balakumaran N.A   11 years AGO

Area of equilateral triangle is:
A^2 * Sqrt (3) / 4 = 25 Sqrt (3) cm^2
then, A = 10 cm.
Perimeter is 3 * A = 30 cm. (A is side of equilateral triangle)...

Like? Yes (1) | No   

Bibhash   11 years AGO

Area = 43.30 cm2
Area =root3/4*a2
a= 9.99=10
perimeter= 3a
= 3*10=30

Like? Yes (1) | No   

dan   11 years AGO

Let the triangle is of a cm on each side.
the height is h=a/2*tan60=a*(sqrt3/2)
Area=1/2*a*h=1/2*a*a(sqrt3/2)=(a^2)*sqrt3*(1/4) cm^2

As, (a^2)*sqrt3*(1/4)=25 sqrt3
solving we get, a=10 cm
perimeter=10*3=30 cm

Like? Yes (1) | No   

sanjay singh   11 years AGO

let each side of triangle=a
sq.rt.3/4*a^2=25*sq.rt.3

a^2=25*4=100
a=10
3a=30

Like? Yes (1) | No   

seema sarkar   11 years AGO

side =10

Like? Yes (1) | No   

tejaswini g   11 years AGO

area of equillateral triangle is=(sqrt3/4)S^2
25*sqrt3=(sqrt3/4)S^2
S^2=25*4
s=10
perimeter=3*s=3*10=30cm

Like? Yes (1) | No   

Himanshu Jain   11 years AGO

25*sqrt(3) = (sqrt(3)*a^2)/4 [area of an equilateral triangle, where a = side) solving for a gives perimeter = 3*10 = 30

Like? Yes (1) | No