Saved Bookmarks
| 1. |
The sides of a right-angled triangle containingthe right angle are 4x cm and (2x - 1) cm. Ifthe area of the triangle is 30 cm2; calculate thelengths of its sides. |
|
Answer»
Area of triangle = 1/2 ×base × height
➝ 30 = 1/2 ×4x × (2x -1) ➝ 30 × 2 = 4x × (2x -1) ➝ 60 = (4x)(2x-1) ➝ 60/4 = x(2x-1) ➝ 15 = 2x² - x ➝ 2x² - x -15 = 0 Now solving EQUATION for x ➝ 2x² - 6x + 5x -15 ➝ 2x (x - 3) +5(x - 3) ➝ (2x + 5) (x -3)
Length of any side cannot be negative . So, x = 3 Base = 4x ⠀⠀⠀⠀ = 12cm Height = 2x-1 ⠀⠀⠀⠀⠀ = 5 cm we know that , according to question the triangle is RIGHT angled triangle. So, hypotenuse² = base² + perpendicular² ➝ H² = 12² +5² ➝ H² = 144 +25 ➝ H² = 169 ➝ H = √169 ➝ H = 13, So, All sides of triangle are 12 cm , 5cm ,and 13cm ━━━━━━━━━━━━━━━━━━━━━━━━━ |
|