EduFarming
Your list · 0हिं

Type at least two letters. Press Esc to close.

↑↓ navigate↵ openTAB cycle filter

Mensuration: Areas and Volumes · Question 27 of 68

Question 27

HardOriginal question

A sector of a circle of radius 14 cm has a perimeter of 50 cm (two radii plus the arc). What is the area of the sector? Take π=227\pi = \frac{22}{7}.

Options for question 27

Show the answer and explanation
CorrectNot quiteAnswer A

Correct answer: A

Explanation

  1. Arc length = 50−2×14=2250 - 2 \times 14 = 22 cm.

  2. The full circumference is 2×227×14=882 \times \frac{22}{7} \times 14 = 88 cm, so the sector is 22/8822/88 = ¼ of the circle.

  3. Area = 14×227×14×14=154\frac{1}{4} \times \frac{22}{7} \times 14 \times 14 = 154 cm². (Shortcut: area = ½ × arc × radius = 12×22×14\tfrac{1}{2} \times 22 \times 14.)

Worth noting

350 cm² puts the whole perimeter, 50 cm, into ½ × arc × radius. Only the curved part is the arc.

Concept
Sector area = ½ × arc length × radius
Typical time
115 s
Your time
—
The rule this testsCircles, rings and sectors
Practise this chapter →

Ten questions from Mensuration: Areas and Volumes, at your own pace.

Practise this chapter →

Ten questions from Mensuration: Areas and Volumes, at your own pace.