What is the area of the region between two concentric circles if the chord of the outer circle of length 14 cm is a tangent of the inner circle? (Take \pi=\frac{22}{7})

Explanation

Let the outer radius be R and the inner radius be r. The chord is tangent to the inner circle, so the perpendicular from the center bisects the chord. By Pythagoras, R^2 - r^2 = (14/2)^2 = 49. The area between them is \pi R^2 - \pi r^2 = \pi(R^2 - r^2) = \frac{22}{7} \times 49 = 154 sq cm.

Related questions on Mensuration

• A pendulum swings through an angle of 30° and its end describes an arc of length 55 cm. What is the length of the pendulum? (Take $\pi = 22/...
• A conical tent has an angle of 60° at the vertex. If the curved surface area is 100 m^2, then what is the volume of the tent?
• A right circular cone and a hemisphere have equal base and equal volume. What is the ratio of the height of the cone to the radius of the he...
• A wire is in the form of an equilateral triangle with an area of 36\sqrt{3} cm^2. If it is changed into a semicircle, then what is its r...
• Let the area of the largest possible square inscribed in a circle of unit radius be x. Let the area of the largest possible circle inscribed...