1. In ΔABC, ∠A = 50° and the external bisectors of ∠B and ∠C meet at O as shown in figure. The measure of ∠BOC is

2. In figure the value of x is

3. An exterior angle of a triangle is 80° and the interior opposite angles are in the ratio 1 : 3, measure of interior opposite angles are

4. In ΔABC, the bisectors of ∠ABC and ∠BCA intersect each other at O. The measure of ∠BOC is

5. In figure if ∠A + ∠B + ∠C + ∠D + ∠E + ∠F = k right angles, then find value of k.

6. In the given figure, the measure of ∠ABC is

7. The angle of a triangle are in the ratio 5 : 3 : 7, the triangle is

8. In figure l₁ || l₂, the value of x is

9. If one angle of triangle is equal to the sum of the other two, then the triangle is

10. One of the angles of a triangle is 75°. If the difference of other two is 35°, then the largest angle of other two angles has a measure