Penelope has a square piece of paper KLMN of side 35 m. She cut along the dotted lines shown in Figure 1 to get one small square of area 25 m
2 and 8 identical right-angled triangles. Triangle PQR in Figure 2 is one such triangle. Find the length of PR.
Area of the square piece of paper
= 35 x 35
= 1225 m
2 Area of 8 triangles
= 1225 - 25
= 1200 m
2Area of 4 outer triangles
= 1200 ÷ 2
= 600 m
2 Area of the inner dotted-line square
= 1225 - 600
= 625 m
2 Length of inner dotted-line square
= √625
= 25 m
Length of PR = 25 m
Answer(s): 25 m