Question

If RSTW is a rhombus, what is the area of
△WXT? A.)18 square root3 B.)36 square root 3 C.)36 D.)48

Answer 1

diagram ??

Answer 2

Have you learned to use sine or cosine yet?

Answer 3

yeah

Answer 4

Okay then, you can find the base and height of that triangle, then the area of the triangle is half base times height.

\[A = \frac{ 1 }{ 2 } b \times h\]



Cosine is adjacent/hypotenuse, so
\[\cos 60 = \frac{ b }{ 12 }\] sine is opposite/adjacent, so \[\sin60 = \frac{ h }{ 12}\]

Answer 5

How do i know which one to use?
Does it matter?

Answer 6

What do you mean? You need both b and h to use in the A=0.5bh

Answer 7

Well for the angle, do I use sin or cosine?

Answer 8

You have to use both, as I showed in the last post.

Answer 9

Cosine is adjacent/hypotenuse, so
cos60=b/12
sine is opposite/hypotenuse, so
sin60=h/12

Answer 10

Make sense?

Answer 11

sort of

Answer 12

Remember that sine = opposite/hypotenuse? And cosine = adjacent/hypotenuse?

Answer 13

oh well yeah i got that part

Answer 14

So then, knowing that, \[\cos 60 = \frac{ b }{ 12 }\] and \[\sin60 = \frac{ h }{ 12}\]

Answer 15

Because b is adjacent to the angle, h is opposite to the angle, and 12 is the hypotenuse.

Answer 16

(since it's a right triangle and the diagonals of a rhombus intersect at right angles)

Answer 17

Follow or no?

Answer 18

yes

Answer 19

Okay, so now you can try to find b and h from \[\cos 60 = \frac{ b }{ 12}\] \[\sin60 = \frac{ h }{ 12} \]

Answer 20

For both, you can multiply both sides by 12