Answer:
20%
Step-by-step explanation:
First step is counting all of the people up, I came up with 60. Then we have to construct our equation(12/60). Then you multiply it by 100. What you get is the percentage, 120/6 is 20. So the answer is 20%.
RO divides the rectangle into two congruent right triangles.
The area of the one triangle is equal half area of the rectangle.
Calculate the area of rectangle:

The area of right triangle:

Use the Pythagorean theorem to calculate the length of RO:

The formula of an area of this right triangle is:

Therefore we have the equation:

The answer would be b-5+6