What is the area (in cm²) of the circumcircle of a triangle whose sides are 6 cm, 8 cm and 10 cm respectively?

ABC is an isosceles triangle with AB = AC, A circle through B touching AC at the middle point of Q, intersects AB at P. Then AP : AB is : 

If ABCDEF is a regular hexagon, then what is the value (in degrees) of ∠ADB? 

If two complimentary angles are in the ratio of 4:5, find the greater angle.

If the ratio of the measurements of the three angles of a triangle is 2: 3: 4, then the measurement of its largest angle is.

If one angle is half of its complementary angle, find that angle.

If ABC is an equilateral triangle and P, Q, R respectively denote the middle points of AB, BC, CA, then