If the angles are in the ratio `5 : 3 : 7,` then the triangle isA. an acute angled triangleB. an obtuse angled triangleC. a right angled triangleD. an isosceles triangle

If the angles are in the ratio `5 : 3 : 7,` then the triangle isA. an

1.	If the angles are in the ratio `5 : 3 : 7,` then the triangle isA. an acute angled triangleB. an obtuse angled triangleC. a right angled triangleD. an isosceles triangle
Answer» Correct Answer - a Given, the ratio of angles of a triangle is `5 : 3 : 7` Let angles of a triangle be `/_A, /_B and /_C.` Then, `" "/_A = 5X,/_B = 3X and /_C = 7x` In `Delta ABC, " " /_A + /_B + /_C = 180^(@) ["since, sum of all angles of a triangle is" 180^(@)]` `:. " " 5x + 3x +7x = 180^(@)` `rArr " " 15x = 180^(@)` `rArr " "x = 180^(@)/15 = 12^(@)` `:. " " /_A =5x = 5xx12^(@) = 60^(@)` `/_B = 3x = 3xx12^(@) = 36^(@)` and `" " /_C = 7x = 7xx12^(@) = 84^(@)` Since, all angles are less then `90^(@)`, hence the triangle is an acute angled triangle .