Question

If the sides of an equilateral triangle are increased by 20%, 30% and 50% respectively to form a new triangle, what is the percentage increase in the perimeter of the equilateral triangle?​

Answer 1

Answer:

33(1/3% )

Step-by-step explanation:

Perimeter of equilateral triangle

=100+100+100=300

Perimeter of New triangle

=120+150+130=400

% increase =100300×100

=33(1/3)%

Answer 2

Answer:

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

Let the sides of the equilateral triangle be x cm. Then, after increase the three sides are

x + 20/100x, x + 30/100x and x + 50/100x,

i.e., x + 0.2x, x + 0.3x and x + 0.5x,

i.e., 1.2x, 1.3x and 1.5x.

Therefore Original perimeter = 3x,

Increased perimeter = 1.2x + 1.3x + 1.5x = 4x

Percent increase in perimeter =(Increase in perimeter ÷ Original perimeter) × 100

$= \frac{(4x - 3x)}{(3x)} \times 100\%$

= 100/3%

Hence percent increase in the perimeter of the equilateral triangle

= 100/3%