A 120° sector of a circle of radius 21cm is bent to f...
A 120° sector of a circle of radius 21cm is bent to form a cone. What is the base radius of the cone?
31/2cm
7cm
1O1/2cm
14cm
21cm
Correct answer is B
The length of the arc subtended by the sector of angle 120° = circumference of the base of the cone.
120360×2×227×21=2πr
44=2πr
r=22÷π
r=22×722
r = 7 cm
Calculate the standard deviation of the following data: 7, 8, 9, 10, 11, 12, 13 ...
Solve the equation: 3a + 10 = a2...
Determine the mean score of the student that took the mathematics test?...
The graph of the curve y=2x2−5x−1 and a straight line PQ were drawn to solve the equation...
Evaluate 1 − (15 x 123) + (5 + 123)...
\(\begin{array}{c|c} Age(years) & 13 & 14 & 15 & 16 & 17 \\ \hline Frequency & 10 & 24 & 8 & 5...