1 In a sale, normal prices are reduced by 25%.
The sale price of a washing machine is £374.25.
Work out the normal price of the washing
machine.

Apply sine theorem:

1.

c/sinC = a/sinA

=> sinC = sinA x (c/a) = sin70 x 28/24 = 1.096 => Invalid ( 1.096 > 1)

=> C is undefined

=> B is undefined

2.

c/sinC = b/sinB

=> sinB = sinc x (b/c) = sin40 x 34/33 = 0.662

=> B = arcsin(0.662) = 41.47 deg

3.

c/sinC = b/sinB

=> sinB = sinC x (b/c) = sin29 x 26/6 = 2.101 => Invalid ( 2.101 > 1)

=> B is undefined

=> A is undefined

4.

c/sinC = a/sinA

=> sinC = sinA x (c/a) = sin28 x 20/16 = 0.587

=> C = arcsin(0.587) = 35.93 deg

Hope this helps!

:)