Year 10 5.3: the sine rule for angles (1 Viewer)

[jane1820]

i dont get why the answer for 5.a. says that theta can be either 75 degrees or 117 degrees when the question specified that the angle is acute? i understand the ASTC rule which is: since sine is positive it can either be A (the angle itself) or S 180 - the angle
but i dont understand how the S is applicable here since the question said that theta is actue
is this a typo?

 

[Study to success]

Maybe it's because they want you to give the obtuse solution as well because sine can be obtuse when it is positive and can also be acute

 

[nonya2000]

i dont get why the answer for 5.a. says that theta can be either 75 degrees or 117 degrees when the question specified that the angle is acute? i understand the ASTC rule which is: since sine is positive it can either be A (the angle itself) or S 180 - the angle
but i dont understand how the S is applicable here since the question said that theta is actue
is this a typo?
View attachment 44443View attachment 44444

I know this textbook, it's New Century 10A

 

[WeiWeiMan]

i dont get why the answer for 5.a. says that theta can be either 75 degrees or 117 degrees when the question specified that the angle is acute? i understand the ASTC rule which is: since sine is positive it can either be A (the angle itself) or S 180 - the angle
but i dont understand how the S is applicable here since the question said that theta is actue
is this a typo?
View attachment 44443View attachment 44444

cuz textbook solutions can be wrong