Hi! So what you will need to know is pythagorean theorm.
What the theorm basically says is a^2 + b^2 = c^2.
-- The (a,b,c) are referring to the sides of the triangles (3 letters for 3 sides).
Take note that "c" is always the side opposite of the right angle.
The other known side could be "a" or "b"
Taking a look at problem 9, identify the "c" value. The "c" value would be 35.
Then indentify the value of "b" or "a". "a" would = 20.
Plug it into the equation:
20^2 + b^2 = 35^2
400 + b^2 = 1225
solve for b.
1. subtract 400 from both sides.
b^2 = 825
b =
you could solve for the square root but it would give a decimal numbers but I'm not sure what the teacher is looking for.