Sec 3 E. Maths Question

• BillaMax

  9 Sep 10, 20:17

  

  Hi, how to do part 3 of the question? (c)

• Forbiddensinner

  9 Sep 10, 21:42

  Originally posted by BillaMax:

  

  Hi, how to do part 3 of the question? (c)

  Notice that OC and OD are radius of the circle.

  Thus, OCD is an isoceles triangle, meaning that angle ODC = angle OCD.

  angle COD is 40 degrees, so angle ODC = 70 degrees

  I could be wrong, but PDQ seems like a tangent to the circle, so angle ODP is 90 degrees.

  Hence, angle CDP = ODP - ODC = 90 - 70 = 20 degrees

   

  Edie: PDQ is a tangent. D lies on the circle and PDQ is a straight line.

• Xpoloppx

  20 Sep 10, 16:25

  how you get a)?