Question

4. By decreasing 15° of each an- gle of a triangle, the ratios of their angles are 2:3 : 5, The radian measure of greatest angle is : N

11th - 12th Class

Maths

Solution

160

4.0 (1 ratings)

4. (I) ( 2 x+3 x+5 x=180^{circ}-45^{circ} ) ( =135^{circ} ) ( Rightarrow 10 x=135^{circ} ) ( Rightarrow x=frac{135}{10}=frac{27}{2} ) ( therefore ) Largest angle ( =5 x+15^{circ}=left(5 times frac{27}{2}right)^{circ}+15^{circ} ) ( =frac{135+30}{2}=frac{165^{circ}}{2} ) ( because 180^{circ}=pi mathrm{radian} ) ( therefore frac{165^{circ}}{2}=frac{pi}{180} times frac{165}{2}=frac{11 pi}{24} ) radian