This question was asked by m friend Sopie. I am not able to solve it. Can anyone help? See attachment
not in order and may be incomplete ABC =180 -60 = 120 ACB = 180- (25 + 120) = 180 - 145 = 35 AC = BD BDC =25 given AD = 65 DA is perpendicular to AE 65 + 25 = 90 = DAB
@triciaal why AC=BD?
BC parallel to AD Chord BC similar figures ABC and DCB
How BC paralll to AC? impossible
@triciaal
do u have a screenshot? i cant open the document... :-/
there are a few ways to find angle ADC. one way: i) <CBE is an exterior angle of triangle ABC, so it equals the sum of the "opposite" angles: <CBE= <BAC + <BCA 60 = 25 + <BCA so <BCA= 60-25= 35 ii) inscribed angle <ACD = 1/2 arc BC + 1/2 arc AB from part i) we can find arc BC and arc AB, and so we can find angle ACD
for part (b), angle ADB is 1/2 arc AB which we know from part (a) for part (c), angle CAB= 65+25= 90 i.e. a right angle. if the inscribed angle is 90 degrees, then the chord is a diameter.
in general, use the the idea that inscribed angles that subtend the same arc are equal |dw:1439469998213:dw|
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