The radius of a circle whose circumference is equal to the sum of the circum- ferences of the two circles of diameters 36cm and 20 cm is
(A) 56 cm (B) 42 cm (C) 28 cm (D) 16 cm
The area of the circle that can be inscribed in a square of side 6 cm is
(A) 36 π cm2 (B) 18 π cm2 (C) 12 π cm2 (D) 9 π cm2
It is proposed to build a single circular park equal in area to the sum of areas of two circular parks of diameters 16 m and 12 m in a locality. The radius of the new park would be
(A) 10 m (B) 15 m (C) 20 m (D) 24 m
If the perimeter of a circle is equal to that of a square, then the ratio of their areas is
(A) 22 : 7 (B) 14 : 11 (C) 7 : 22 (D) 11: 14
If the circumference of a circle and the perimeter of a square are equal, then
(A) Area of the circle = Area of the square
(B) Area of the circle > Area of the square
(C) Area of the circle < Area of the square
(D) Nothing definite can be said about the relation between the areas of the circle and square.
If the sum of the circumferences of two circles with radii R1 and R2 is equal to the
(A) R1 + R2 = R (B) R1 + R2 > R
(C) R1 + R2 < R (D) Nothing definite can be said about the relation among R1, R2 and R.
If the area of a circle is 154 cm2, then its perimeter is
(A) 11 cm (B) 22 cm (C) 44 cm (D) 55 cm
Draw a triangle ABC in which AB = 4 cm, BC = 6 cm and AC = 9 cm. Construct a triangle similar to ∆ABC with scale factor 3/2 . Justify the construction. Are the two triangles congruent? Note that all the three angles and two sides of the two triangles are equal.
Draw a circle of radius 4 cm. Construct a pair of tangents to it, the angle between which is 60º. Also justify the construction. Measure the distance be- tween the centre of the circle and the point of intersection of tangents.