The sum of the three angles of a triangle is `180^@`

Which of the following statements are true (T) and which are false (F): Sum of the three angles of a triangle is 180^0 A triangle can have two right angles. All the angles of a triangle can be less than 60^0 All the angles of a triangle can be greater than 60^0 All the angles of a triangle can be equal to 60^0 A triangle can have two obtuse angles. A triangle can have at most one obtuse angles. In one angle of a triangle is obtuse, then it cannot be a right angled triangle. An exterior angle of a triangle is less than either of its interior opposite angles. An exterior angle of a triangle is equal to the sum of the two interior opposite angles. An exterior angle of a triangle is greater than the opposite interior angles

We know that the sum of the interior angles of a triangle is 180^(@). Show that the sums of the interior angles of polygons with 3,4,5,6 sides form an arithmetic progression.Find the sum of the interior angles of a 21 sided polygon.

The sum of the angles of a triangle is .......

The sum of the angles of a triangle is .......

Theorem 6.7 : The sum of the angles of a triangle is 180º

The sum of the two angles of the triangle is 90^(@) then find the third angle?

Solve the following: (a) The teacher tells the class that the highest marks obtained by a student in her class is twice the lowest marks plus 7. The highest score is 87. What is the lowest score? (b) In an isosceles triangle, the base angles are equal. The vertex angle is 40°. What are the base angles of the triangle? (Remember, the sum of three angles of a triangle is 180°). (c) Smita’s mother is 34 years old. Two years from now mother’s age will be 4 times Smita’s present age. What is Smita’s present age? (d) Sachin scored twice as many runs as Rahul. Together, their runs fell two short of a double century. How many runs did each one score?

Which of the following sentences are statements ? Give reason for your answer. The sum of all interior angles of a triangle is 180^(@) .