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circles properties..
Fireindahouse
2 Oct 07, 15:12
i need help with part b(iii) pretty pls.
wishboy
2 Oct 07, 15:36
(a) 90° (angle in semicircle)
(b)
(i)
sin angleOAB = 6/13
angleOAB = 27.5°
(ii)
tan 27.486° = 15/AC
AC = 28.8 cm
(iii)
sin 27.486° = ½CE/28.832
CE = 26.6 cm
for part (iii), there is another right angle triangle formed by the tangent and the vertical line across the big circle
davidche
2 Oct 07, 17:53
Im too lazy to do for you.
Some pointers, the tangents are right angled to the radius.
the whole figure is full of similar figures.
try using simple pythagares(sp.).