Answer: The ladder would reach 15.3 ft up the wall
Step-by-step explanation: Please refer to the attached diagram.
If the ladder (represented by line AC) rests on the wall (represented by line AB), it forms an angle of 50 with the ground (at point C). The ground is represented by line BC.
We need to remember that we have one side and one angle given in this question. The given side is the hypotenuse (the side facing the right angle, B in this case) and the given angle is the reference angle. The unknown side which is x, is the opposite as it is facing the reference angle.
Having the opposite and the hypotenuse, we can use the Sine ratio which is,
Sine C = opposite/hypotenuse
Sine 50 = x/20
Checking our table of values or by use of our calculator, sin 50 is 0.766
Sin 50 = x/20
0.766 = x/20
By cross multiplication, we now have our equation rewritten as;
0.766 (20) = x
15.32 = x
Rounded to the nearest tenth,
x = 15.3 ft