The sector of a circle has radius of 21 cm and central angle 135o. Find its perimeter?
Correct answer: A. 91.5 cm
- A. 91.5 cm
- B. 93.5 cm
- C. 94.5 cm
- D. 92.5 cm
Explanation
The arc length is (135°/360°) x 2π x 21 cm = 15.75π cm = 49.5 cm, using π = 22/7. The sector perimeter is two radii plus the arc, so 21 cm + 21 cm + 49.5 cm = 91.5 cm. Option b usually results from an arithmetic error in the arc length.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Area and Volume
Area measures the surface enclosed by two-dimensional figures, while volume measures the space occupied by three-dimensional solids. Problems use formulas for rectangles, triangles, circles, prisms, cylinders, cones, spheres, and composite figures, including unit conversion and the distinction between surface area, lateral area, and volume.
Practise Geometry
222 free Geometry MCQs from Mathematics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Mathematics questions like this
Mathematics is on 76 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Area and Volume questions
An order was placed for the supply of a carper whose length and breadth were in the ratio of 3 : 2. Subsequently, the dimensions of the carpet were altered such that its length and breadth were in the ratio 7 : 3 but were was no change in its parameter. Find the ratio of the areas of the carpets in both the cases.
Surface area of a sphere is 2464 cm2. If its radius is doubled, then the surface area of _________?the new sphere will be
A large cube is formed from the material obtained by melting three smaller cubes of 3, 4 and 5 cm side. What is the ratio of the total surface areas of the smaller cubes and the large cube?
The length of a rectangle is two - fifths of the radius of a circle. The radius of the circle is equal to the side of the square, whose area is 1225 sq.units. What is the area (in sq.units) of the rectangle if the rectangle if the breadth is 10 units?
The ratio of the volumes of two cubes is 729 : 1331. What is the ratio of their total surface areas?
A metallic sphere of radius 12 cm is melted and drawn into a wire, whose radius of cross section is 16 cm. What is the length of the wire?