1mark 2019 CA1 P6 Paper1 River Valley P6 / River Valley / 2019 / CA1 / Paper 1 – Q04 [1 mark] Question: Which two lines in the square grid below are perpendicular to each other? Solution: Similar Posts P6 / Ai Tong / 2020 / SA2 Prelims / Paper 1 – Q21 [2 marks] P6 / Nan Hua / 2021 / SA2 / Paper 1 – Q30 [2 marks]