Advertisements
Advertisements
Question
Find the missing values in the following table for the circles with radius (r), diameter (d) and Circumference (C).
| radius (r) | diameter (d) | Circumference (C) |
| 15 cm |
Advertisements
Solution
Given: radius r = 15 cm
∴ diameter d = 2 × 15 = 30 cm
Circumference C = πd units
= `22/7 xx 30`
= `660/7`
= 94.28 cm
Tabulating the results
| radius (r) | diameter (d) | Circumference (C) |
| 15 cm | 30 cm | 94.28 cm |
APPEARS IN
RELATED QUESTIONS
Two circles touch each other externally at P. AB is a common tangent to the circles touching them at A and B. The value of ∠ L APB is
(A) 30°
(B) 45°
(C) 60°
(D) 90°
In Fig. 8, O is the centre of a circle of radius 5 cm. T is a point such that OT = 13 cm and OT intersects circle at E. If AB is a tangent to the circle at E, find the length of AB, where TP and TQ are two tangents to the circle.
Write True or False. Give reasons for your answers.
A chord of a circle, which is twice as long as its radius, is a diameter of the circle.
O is the center of a circle of radius 8cm. The tangent at a point A on the circle cuts a line through O at B such that AB = 15 cm. Find OB
In Fig. 4, an isosceles triangle ABC, with AB = AC, circumscribes a circle. Prove that the point of contact P bisects the base BC.
In Fig. 5, the chord AB of the larger of the two concentric circles, with centre O, touches the smaller circle at C. Prove that AC = CB.
If ABCD is a cyclic quadrilateral in which AD || BC (In the given figure). Prove that ∠B = ∠C.
Find the area of a circle of radius 7 cm.
In the given figure, O is the centre of a circle, chord PQ ≅ chord RS If ∠ POR = 70° and (arc RS) = 80°, find –
(1) m(arc PR)
(2) m(arc QS)
(3) m(arc QSR)
In the given figure, seg MN is a chord of a circle with centre O. MN = 25, L is a point on chord MN such that ML = 9 and d(O,L) = 5. Find the radius of the circle.
Construct a triangle ABC with AB = 4.2 cm, BC = 6 cm and AC = 5cm. Construct the circumcircle of the triangle drawn.
In the table below, write the names of the points in the interior and exterior of the circle and those on the circle.
| Diagram | Points in the interior of the circle |
Points in the exterior of the circle |
Points on the circle |
 |
The radius of a circle of diameter 24 cm is _______
AB and AC are two equal chords of a circle. Prove that the bisector of the angle BAC passes through the centre of the circle.
O is the circumcentre of the triangle ABC and D is the mid-point of the base BC. Prove that ∠BOD = ∠A.
The circumcentre of the triangle ABC is O. Prove that ∠OBC + ∠BAC = 90º.
If ABC is an equilateral triangle inscribed in a circle and P be any point on the minor arc BC which does not coincide with B or C, prove that PA is angle bisector of ∠BPC.
From the figure, identify a diameter.
From the figure, identify two points in the interior.
Which of the following describes the radius of a circle?
