Julie has a square piece of paper QRST of side 63 m. She cut along the dotted lines shown in Figure 1 to get one small square of area 81 m
2 and 8 identical right-angled triangles. Triangle UVW in Figure 2 is one such triangle. Find the length of UW.
Area of the square piece of paper
= 63 x 63
= 3969 m
2 Area of 8 triangles
= 3969 - 81
= 3888 m
2Area of 4 outer triangles
= 3888 ÷ 2
= 1944 m
2 Area of the inner dotted-line square
= 3969 - 1944
= 2025 m
2 Length of inner dotted-line square
= √2025
= 45 m
Length of UW = 45 m
Answer(s): 45 m