Question

What percent area will increase if the sides of triangle is double?

Answer 1

Area of triangle = 0.5 × base × height

Area ∝ (L)²

A₂/A₁ = (L₂/L₁)²
A₂/A₁ - 1 = (L₂/L₁)² - 1
ΔA/A₁ = (L₂/L₁)² - 1

%ΔA/A₁ = [(L₂/L₁)² - 1] × 100]
= [(2L/L)² - 1] × 100
= 300%

∴ Area will increase by 300%