1. Let us evaluate:
2. Let us show that:
2.
3. If two angles α and β are complementary angles, let us show that
4. If sin 17o = x/y, let us show that ;
5. let us show that; 
6. ∠A + ∠B =90o, let us show that ;
7. let us show that ;
8. If ∠P + ∠Q = 90o, let us show that ;
9. let us prove that ;
10. AOB is a diameter of a circle with center O and C is any point on the circle, joining A.C, B,C and O,C let us show that;
10.
11. ABCD is a rectangular figure, joining A, C let us prove that.
