Answer:
m<B=39°
Explanation:
First we need to find x.
One important thing you need to know to solve this question is that all the angles in a triangle add up to 180°. So :
m<A + m<B + m<C =180°
Let's sub in 90 for m<A since it's a right angle, and sub in the marked expressions for m<B and m<C respectively:
m<A + m<B + m<C =180°
90 + (2x+11) + (4x-5) =180
90+11-5 + 2x + 4x =180
96+6x=180
6x=84
x=14
No that we know x we can sub this into our expression for m<B to find the answer:
m<B=(2x+11)°
m<B=(2(14)+11)°
m<B=(28+11)°=39°