Question

I need help thank you

Answer 1

Answer:

Step-by-step explanation:

Use SOH CAH TOA to recall how the trig functions fit on a triangle

SOH: Sin(Ф)= Opp / Hyp

CAH: Cos(Ф)= Adj / Hyp

TOA: Tan(Ф) = Opp / Adj

we can find angle C  b/c the angles of a triangle always add to 180 , soo

180= C + 81 +63.5

35.5 = C

now that we have angle C and we know the Hyp we can use sin to find side g

where g = Opp and Hpy = 13.8 for this question

Sin(35.5) = Opp / 13.8

13.8*Sin(35.5) = Opp

8.0137 = Opp

g = 8.0137

next they ask for the area of the biggest triangle  ABC ( there are two smaller ones when you use D )

we can use 1/2 * base * height , but we don't know the base yet, even thou we do know the height.  

we can solve for line segment CD and DB and then add them for the side a .. or the base of the biggest triangle sooo.. CD = adj

Cos(35.5) = Adj / 13.8

13.8*Cos(35.5) = Adj

11.234794 =Adj

now solve for DB using cos again but with the other smaller triangle where  Adj = DB now

Cos(63.5) = Adj / 8.9

8.9*Cos(63.5) = Adj

3.971160

add these two Adjs together to get the total  'a' side

15.205954

now plug in side a as the base and g as the height of our biggest triangle

Area = 1/2 * 15.205954 * 8.0137

Area = 60.9159

rounded to 2 sig figs

Area = 60.92   :)   hope you get an "A"    :P