# maths

posted by
**kat**
.

Choose three options which are true:

a) an angle of 150 degrees is equivalent to 2pie/3 radians.

b) Cos 0 = cos (0 – pie/2) for al values of 0.

c) Sin 0 = cos (0 – pie/2) for all values of 0.

d) If triangle ABC has a right angle at B, then sin A = cos C

e) In any triangle ABC, if the lengths of just two sides of the triangle are known, then you always calculate the third.

f) In any triangle ABC,AB sin C = AC sin B

g) If triangles PQR and XYZ are similar, with P = X, Q = Y, R = Z, then XY/PQ = XZ/PR

h) In any triangle PQR, cos R = PR^2 + PQ^2 – QR^2/ 2 x PR x PQ.

would it be D and E and F ??

e is obviously false.

d is true

f is not the law of sines I learned. AB is side c, and AC is side b.

c*SinC is not equal to b*SinB.

c/SinC= b/SinB is the law of sines.