Geometry 8th gr
posted by Mona on .
Given: triangle ABC ~ triangle PQR, m<A = 75 degrees, m<P = (5x + 7y) degrees, m<R = (3x + 4y) degrees, and m<B =( 2x + 9y) degrees. FInd m<R.
Thanks

very similar to the one I did for you yesterday.
draw the two triangles and fill in the information.
5x + 7y = 75  equation #1
In triangle AC
angle C = 180  75  2x  9y
= 105  2x  9y
3x+4y = 105  2x  9y
5x + 13y = 105  #2
subtract #2  #1
6y = 30
y = 5
back into #1
5x + 35 = 75
5x = 40
x=8
so if x=8 and y=5
angle R = 3x+4y = 24+20 = 44°
check: 5x + 7y should be 75
5(8) + 7(5) = 75 , yeahhh 
Okay, I get it now:)...thanks.