Wendy has a square piece of paper EFGH of side 42 m. She cut along the dotted lines shown in Figure 1 to get one small square of area 36 m
2 and 8 identical right-angled triangles. Triangle JKL in Figure 2 is one such triangle. Find the length of JL.
Area of the square piece of paper
= 42 x 42
= 1764 m
2 Area of 8 triangles
= 1764 - 36
= 1728 m
2Area of 4 outer triangles
= 1728 ÷ 2
= 864 m
2 Area of the inner dotted-line square
= 1764 - 864
= 900 m
2 Length of inner dotted-line square
= √900
= 30 m
Length of JL = 30 m
Answer(s): 30 m