The angle formed at the centre of the circle by lines originating from two points on the circle's circumference is double the angle formed on the circumference of the circle by lines originating from the same points. But x + y is the size of the angle we wanted to find.Ī tangent to a circle is a straight line which touches the circle at only one point (so it does not cross the circle- it just touches it).Ī tangent to a circle forms a right angle with the circle's radius, at the point of contact of the tangent.Īlso, if two tangents are drawn on a circle and they cross, the lengths of the two tangents (from the point where they touch the circle to the point where they cross) will be the same. Join fellow readers for a book club discussion facilitated by our Childrens and Teens Specialist, Laura. HUGE Tangent Template Update (CreateSpace and KDP book building tool). Therefore x + y + x + y = 180, in other words 2(x + y) = 180.Īnd so x + y = 90. Not only that, but we have a wide selection of freebies and bonuses in our Gumroad. Therefore each of the two triangles is isosceles and has a pair of equal angles.īut all of these angles together must add up to 180°, since they are the angles of the original big triangle. We know that each of the lines which is a radius of the circle (the green lines) are the same length.

Solution: When the angle is beyond 360°, then we find its coterminal angle by adding or subtracting multiples of 360° to get the angle to be within 0° and 360°. We can split the triangle in two by drawing a line from the centre of the circle to the point on the circumference our triangle touches. Example 2: Use the unit circle with tangent to compute the values of: a) tan 495° b) tan 900°.

Where Tangents Meet by NOT A BOOK