Question

Hi, this is my moms account I need help with a question I will fan and do a testimonial and best response if you help

Answer 1

In triangle DEF measurement angle D=45 degrees meausrement angle E=63 degrees and EF= 24 inches. What is DE to the nearest tenth of a inch

Answer 2

there isnt a drawing

Answer 3

Hey so I think we can make a triangle as such, so we have an idea what we're looking for :)

Answer 4

Okay so we are looking for x

Answer 5

Yes, I just put a big question mark there instead so we know :), ok lets find the third angle first, and this seems like a sine law problem, so can you first tell me how many degrees are in a triangle?

Answer 6

90

Answer 7

Not quite, you may be thinking of a right triangle which is 90 degrees, but all triangles add up to 180, so our equation for the third angle would be as follow \[45 + 63 + x = 180 \]

Answer 8

oh im sorry...so i would add 45 and 63 then subtract from 180?

Answer 9

So just for convenience our third angle will be 72 degrees ok so we have to use the sine law here, which can be used in any triangle where we have a side and its opposite angles, and yes!

Answer 10

whats next?

Answer 11

\[\frac{ a }{ \sin(A) } = \frac{ b }{ \sin(B) }\] where A and B are known angles.