Expert: Sherman D. - 3/3/2005

Question
A chord of length 19 cm long, cuts an arc creating a right angle. Find the length from the centre of the circle to the chord.

Answer
Distance from center of circle to chord's midpoint: d

d = c cot(theta/2)/2

d = 19 * (cot(1.570796327/2))/2

since cot = 1/(tanA)

d = 19 * (1/(tan(1.570796327/2)))/2
d = 19 * (1/(tan(.785398163)))/2
d = 19 * (1/1)/2
d = 19 * 1/2
d = 19/2
d = 8.5cm

If you are wondering what i did, since at the site below, they have theta, which has to be in radians, i just converted 90 degrees into radians, by using (90pi)/180 = (1/2)pi to get the 1.57. Then i just did the rest.

For info, go to http://mathforum.org/dr.math/faq/formulas/faq.circle.html