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kg m s−1
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Ratio of areas of two similar triangles equals the square of the ratio of their corresponding sides: Area Ratio=12:32=1:9. Therefore, Area(ΔPQR)=9×25=225 cm2.
Two similar triangles ΔABC∼ΔPQR with side ratio PQAB=31. Area of ΔABC=25 cm2.
Area(ΔPQR)Area(ΔABC)=(PQAB)2
Ratio of areas of two similar triangles equals the square of the ratio of their corresponding sides: Area Ratio=12:32=1:9. Therefore, Area(ΔPQR)=9×25=225 cm2.
Taking the linear ratio instead of squaring it, i.e., incorrectly computing Area(ΔPQR)=3×25=75 cm2.
Recall the Area Ratio Theorem for Similar Triangles
If two triangles are similar, the ratio of their areas is equal to the square of the ratio of their corresponding sides.
Area(ΔPQR)Area(ΔABC)=(PQAB)2
Substitute the Given Values
We are given that PQAB=31 and Area(ΔABC)=25 cm2. Substitute these into the formula:
Area(ΔPQR)25=(31)2=91
Calculate the Area of ΔPQR
Cross-multiplying to solve for Area(ΔPQR):
Area(ΔPQR)=25×9=225 cm2
C is correct because the area of ΔPQR is calculated as 25×32=225 cm2.
For 2D similar figures, areas scale by the square of the linear scale factor (k2). For 3D similar solids, volumes scale by the cube of the linear scale factor (k3).