Congruency, SMB-016 Igor was designing a shield using 10 congruent (isosceles) triangles, as shown in the diagram below. How many degrees in the angle marked `x`? (3 marks) --- 6 WORK AREA LINES (style=lined) --- Show Answers Only `72^@` Show Worked Solution `text(Angles at centre of circle)\ = 360/10 = 36^@` `text{Since triangles are isosceles:}` `180` `= 36 + 2x` `2x` `= 180-36` `= 144 ` `:. x` `= 72^@`
