Mathematics · Oct / Nov 2020 · Paper 42 · Question 8

[v = ] 40 [w = ] 80 [x = ] 40 [y = ] 100 [z = ] 60 [5]

B1 for each FT angle z as 140 – their w

24 [3]

M2 for 360 – 11x = 2 × 2x oe

or M1 for 360 – 11x seen or obtuse angle KOL = 2 × 2x oe

angle ADX = angle BCX oe same segment oe angle DAX = angle CBX oe same segment oe angle AXD = BXC oe [vertically] opposite oe corresponding angles are equal oe [4]

M2 Accept in any order

M1 for one correct pair with reason If 0 scored,

SC1 for two correct pairs of equal angles identified with incorrect/no reasons A1

8.75 or 8¾ [2]

M1 for 8 7 10 = DX oe 81.8 or 81.78 to 81.79 [4]

5 2 + 7 2 − 8 2

M2 for [cos[BXC] =] oe 2 5 7 × × 2 2 2

or M1 for 8 = 5 + 7 −× × × 2 5 7 cos(...) oe

A1 for 10 70 oe