Before the video I knew what tangents, chords, and secants were. This is all I knew about before watching the video.
After watching video I learned about the tangent/chord theorem. The tangent/chord theorem is if a tangent and a chord intersect on a circle, then the measures of the angles formed are half of the intercepted arcs. So, measure of angle one equals half of measure of arc AB. You can use this to find the measures of angles and arcs. I also learned about the chord intersection theorem. The chord intersection theorem is if two chords intersect in the interior of a circle, then the measure of each angle is half the sum of the intercepted arcs and its vertical angle. So, the measure of angle one equals half of measure of arc CD plus measure of arc AB, or measure of angle two equals half of measure of arc BC plus measure of arc AD. You can use this to find the measures of arcs and the measure of angles. The last theorem I learned about was the secant/tangent intersection theorems. The secant/tangent intersection theorem is if a tangent and secant, two tangents, or two secants intersect in the exterior of a circle, then the measure of each angle is half the difference of the measure of the intercepted arc. So, there are three equations; one for the tangent and secant, one for the secant and secant, and one for the tangent and tangent. The tangent and secant equation is measure of angle one equals half of measure of arc BC minus measure of arc AC. For secant and secant the equation is measure of angle two equals half of measure of arc XY minus of measure of arc WZ. Lastly, for tangent and tangent the equation is measure of angle three equals half of measure of arc XY minus measure of arc WZ. You can use these three equations to find the measure of arc and measure of angles, but you have to make sure you are using the right equation. This is everything that I learned in the video.
Word Count: 353
Questions:
I commented on Leah S.'s blog and Christina B's blog.
For you first question that all you have to do is take 360 and minus it by 130 because 360 is the whole degree measure. For you second question you have to take the measure of the angle and multiply it by 2 to get 198 then you take 360-198 to get 162.
ReplyDeleteFor your second question you need to take 360-192. You get your 192 from adding your 2 original angles...TU=198. Then since we know that it is half of the intercepted arcs we need divide to check your answer. You would get 81, and if you take 81 and multiply it by 2 you would get a final answer of 162, which is letter C.
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