Question

http://i158.photobucket.com/albums/t120/brinazarski2/photo-7.jpg

In the figure above, OX is a radius of the circle with center O. Which of the following triangles has the least area?

A AOX
B BOX
C COX
D DOX
E EOX

I know the answer is A... but why?

Answer 1

lost my answer.....

each of these triangles are isosceles and equal sides are all radii, so their area will depend on the sine of their vertex angle.
area = 0.5 r^2 sin (vertex angle)

the closer the sine is to 90 degrees the greater it is ( maximum value 1)
the vertex of AOX is close to 180 which is small angle in first quadrant so A is least
EOX has small vertex angle but looks less than AOS

Answer 2

follow that?

Answer 3

Yes :)

Answer 4

the sine of an angle varies between 0 to 1 for 0 to 90 degrees

Answer 5

Mhmm

Answer 6

Thank you :)

Answer 7

yw