The pentagon which is in the cirlcle has two angles which are known, one is 50 degrees the other is 80 degrees, you are asked to find the other three angles. I know that in a quadilateral and trapezium all angles add up to 360 degrees and in a trainlge they add up to 180 degrees so what about a pentagon?
2007-09-03 18:51:44 · 2 answers · asked by NaNeC 1 in Science & Mathematics ➔ Mathematics
In a pentagon the angles add up to 540 degrees.
In general, if there are n sides, the angles add up to 180(n-2).
2007-09-03 18:57:41 · answer #1 · answered by Anonymous · 0⤊ 1⤋
Since the pentagon has 5 angles, the angles will add up to 180(5-2) = 180(3) = 540°. More, since it's inscribed in a circle, you can use the rule that the inscribed angle is half the intercepted arc. Suppose angle A is 50°. Then you also know arc BCDE is 100°. Your answer will depend on the placement of the angles that you know, but you'll be able to set up a system of equations and solve it for the other 3 angles. Too bad you couldn't include a diagram.
2007-09-03 19:10:06 · answer #2 · answered by Philo 7 · 0⤊ 1⤋