Risa has a square piece of paper QRST of side 14 cm. She cut along the dotted lines shown in Figure 1 to get one small square of area 4 cm
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
= 14 x 14
= 196 cm
2 Area of 8 triangles
= 196 - 4
= 192 cm
2Area of 4 outer triangles
= 192 ÷ 2
= 96 cm
2 Area of the inner dotted-line square
= 196 - 96
= 100 cm
2 Length of inner dotted-line square
= √100
= 10 cm
Length of UW = 10 cm
Answer(s): 10 cm