Question

Draw a triangle ABC with the lengths of its sides 6 cm, 8 cm and 9 cm.
(a) Draw the circumcircle of ABC by using the perpendicular bisectors of the two sides of lengths 6 cm and 8 cm.
(b) Discuss the accuracy of your drawing by drawing the third perpendicular bisector of ABC.
(c) Use your ruler to estimate the length of the radius of the circle drawn in (a).
(d) Use your answer in (c) and the extended Law of Sines to estimate the size of the internal angles of ABC to four decimal places and find the sum of these values.
(e) Use the cosine rule to obtain the exact length of the radius of the circumcircle of ABC and compare this answer to your answer in (c). Discuss the difference (if any) using your last answer in (d).

Answer 1

Lengths a = 8 cm, b= 9 cm, c = 6 cm

a)

Perpendicular bisectors drawn from a and c. The intersection point of two perpandicular bisectors will be the center of circumcircle.

b)

Another perpandicular bisector drawn from side b, Its also meets at the same inersection point.

c)

Radius of the circle drawn is 4.6 cm

d)

sum of these angles are 179.9999 degree

e)