Question

The perpendicular drawn from one vertex to opposite side of an equilateral triangle is 12cm . Find the perimeter and area of triangle

Answer 1

Step-by-step explanation:

Here AD=12cm

∴ In ΔABD

∠B=60

o

∠AOD=90

o

∠BAD=30

o

∴sin60

o

=

AB

AD

∴

2

3

=

AB

12

∴AB=

3

24

∴AB=8

3

cm

∴ Perimeter of triangle=8

3

×3

=24

3

cm

∴ Area of triangle =

4

3

×(side)

2

cm

2

∴ Area of triangle=

4

3

×(8

3

)

2

∴ Area of triangle=

4

3

×64×3

∴ Area =46

3

cm

2

.

solution

Answer 2

Answer:

ANSWER

Here AD=12cm

∴ In ΔABD

∠B=60o

∠AOD=90o

∠BAD=30o

∴sin60o=ABAD

∴23=AB12

∴AB=324

∴AB=83cm

∴ Perimeter of triangle=83×3

=243cm

∴ Area of triangle =43×(side)2cm2

∴ Area of triangle=43×(83)2

∴ Area of triangle=4