Question

if tje side of equilateral traingle
decreased by 20% then its area will be decreased by
​

Answer 1

Answer:

36%

Step-by-step explanation:

Let the initial side length be a.

Then, area = $\frac{\sqrt3}{4}a^2$

Now it is given that the side length is reduced by 20%.

∴ New side length = a - 20% of a = a - 0.2a = 0.8a

New area = $\frac{\sqrt3}{4}(0.8a)^2$ = $0.64(\frac{\sqrt3}{4}a^2)$

Percentage decrease in area = $\frac{Original area - New area}{Original area}$ × 100

                                                 = 0.36 × 100 = 36%