8 * 24 feet = 192 sq feet per 5 hours
12* 36 = 432 square feet
432 is 2.25 times the area of 192 square feet
So, it takes 5 * 2.25 = 11.25 hours
Let's write miles over hours
80 / 2 = 200/ x
cross multiply
80x = 400
divide both sides by 80
x = 5
It will take 5 hours to cover 200 miles
Hope this helps :)
So there is an identity we'll need to use to solve this:
cos(x+y) = cosxcosy - sinxsiny
replace the numerator with the right hand side of that identity and we get:
(cosxcosy - sinxsiny)/cosxsiny
Separate the numerator into 2 fractions and we get:
cosxcosycosxsiny- sinxsiny/cosxsiny
the cosx's cancel on the left fraction, the siny's cancel on the right fraction and we're left with:
cosy/siny - sinx/cosx
which simplifies to:
coty - tanx
Interior angles of a triangle=180
Exterior angles = 360