Past papers › JAMB 2004 · UME › Question 28 Question JAMB General Maths 2004 Objective Plane mensuration Plane mensuration
An arc of a circle of length 22 cm subtends an angle of 3 x ∘ 3x^\circ 3 x ∘ x x x [ π = 22 7 ] \left[\pi = \frac{22}{7}\right] [ π = 7 22 ]
A 30 ∘ 30^\circ 3 0 ∘ B 60 ∘ 60^\circ 6 0 ∘ C 120 ∘ 120^\circ 12 0 ∘ D 180 ∘ 180^\circ 18 0 ∘
Worked solution (try it first) The circumference is
22 7 × 14 = 44 \frac{22}{7} \times 14 = 44 7 22 × 14 = 44 cm.
An arc of 22 cm is half of it.
So the arc subtends half of
360 ∘ 360^\circ 36 0 ∘ :
3 x = 180 3x = 180 3 x = 180 .
So
x = 60 ∘ x = 60^\circ x = 6 0 ∘ , option B.
Watch out
180 ∘ 180^\circ 18 0 ∘ 3 x 3x 3 x x x x Report a problem with this question