i have a diagram..it shows the sector of a circle the circle has a radius of 10 cm and an arc length of 15 cm calculate the area of the sector?
ALSO Solve Xsquared + 3x - 5 = 0 Give solutions correct to 4 significant figures
2006-12-03 07:22:57 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
15 / (2 * pi * 10) = A / pi * 100
15 / 20 = A / 100
A = 75 exactly
2006-12-03 07:41:27 · answer #1 · answered by ? 6 · 0⤊ 0⤋
For the circle problem, use ratios. That is, if A denotes the area of the sector, then
A/15 = (area of circle)/(circumference of circle).
Since the area of the circle is pi*10^2 and the circumference is 2*pi*10, then a quick calculation should lead you to the exact answer.
Use the quadratic formula and any scientific calculator to answer the second question.
2006-12-03 07:36:58 · answer #2 · answered by the7nt_man 2 · 0⤊ 0⤋
about 75
2006-12-03 07:32:06 · answer #3 · answered by Waverly Pascale 3 · 0⤊ 0⤋