help!

[jen_star_bubble]

can someone help me to solve this question?

A picture is hung symmetrically by means of a string
passing over a nail with its ends attached to two rings
on the upper edge of the picture. The distance
between the rings is 30 cm and the angle between
the two portions is 105.. Find the length of the string.

this qs is from essential maths ex 13 a qs 15

[b^3]

Split the triangle down the middle to form two right angled triagnles, then the string will be the hypotenus of each triangle. So we need to find the length of the hypotneus and then double it.

When we split the triangle down the middle, the angle will be halfed as well as the lenght opposite it, , and with the opposite side to this being . We want the hypotenus, so make that .



Now the length of the string will be as there is two triangles as we split it.

EDIT: If it still doesn't work, check the mode on your calculator, for the values you're putting in here it will need to be in degrees