`A B` is a diameter of a circle and `C` is any point on the circle. Show that the area of ` A B C` is maximum, when it is isosceles.

AB is a diameter of a circle and C is any point on the circumference of the circle, then :

The diameter of a circle whose area is equal to the sum of the areas of the two circles of radii 40 cm and 9cm is

AB is a diameter of circle. P is a point on the semicircle APB. AH and BK are perpendiculars from A and B respectively to the tangents at P. Prove that AH+BK=AB .

In the given figure, AD is a diameter of a circle with centre O and AB is a tangent at A. C is a point on the circle such that DC produced intersects the tangent at B and |__ABD=50^(@) . Find |__COA .

What is the diameter of a circle whose area is equal to the sum of the areas of two circles of radii 40 cm and 9 cm ?

If the pair of lines ax^2 +2 (a + b) xy + by^2 =0 lie along diameters of a circle and divide the circle into four sectors such that the area of one of the sectors is thrice the area of another sectors, then:

The diameter of a circle is 10cm. A chord of length sqrt50 cm is drawn in the circle. Find the area of the major segment.

What is the area of a circle with diameter d?

The diameter of a circle is a line which joins two points on the circle and also passes through the centre of the circle. (In the adjoining figure (Fig 11.12) AB is a diameter of the circle, C is its centre.) Express the diameter of the circle (d) in terms of its radius (r).

Draw any circke and mark point A, B and C such that (a) A is on the circle.