I need help with these questions (see image). Please show workings.

Answer:
r = [tex]\frac{1}{2}[/tex] [tex]\sqrt{l^2+4h^2}[/tex]
Step-by-step explanation:
h bisects l at right angles.
There is a right triangle formed with legs h and [tex]\frac{1}{2}[/tex] l and hypotenuse r
Using Pythagoras' identity, then
r² = ([tex]\frac{1}{2}[/tex] l )² + h²
= [tex]\frac{1}{4}[/tex] l² + h² ← factor out [tex]\frac{1}{4}[/tex]
= [tex]\frac{1}{4}[/tex] (l² + 4h²)
Take the square root of both sides
r = [tex]\sqrt{\frac{1}{4}(l^2+4h^2) }[/tex] = [tex]\frac{1}{2}[/tex] [tex]\sqrt{l^2+4h^2}[/tex]
Answer:
Step-by-step explanation:
Connect the endpoints of the with the center. The formed triangle is isosceles with sides l, r and r.
The height of the triangle h, is the distance between the center of the circle and the midpoint of the chord.
As per Pythagorean theorem we have: