Mrs Tan pins three identical equilateral triangular bunting flags, Flag 1, Flag 2 and Flag 3, along a straight horizontal string. Each flag points upwards and its bottom edge lies flat on the string. Flag 1 is on the left, Flag 2 is in the middle and Flag 3 is on the right. Flag 2 overlaps Flag 1 and also overlaps Flag 3, but Flag 1 and Flag 3 do not touch each other. On the string: • the distance from the left corner of Flag 1 to the left corner of Flag 2 is 15 cm, • the distance from the left corner of Flag 3 to the right corner of Flag 2 is 4 cm, • the distance from the right corner of Flag 1 to the right corner of Flag 3 is 33 cm. The shaded parts are the part of Flag 1 not covered by Flag 2 and the part of Flag 3 not covered by Flag 2. (a) Find the length of one side of a flag. (b) Find the total perimeter of the two shaded parts.
Opening the drawing…
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