triangles

[molly235]

The sides of a triangle measure 5.2 cm, 8 cm and 8.4 cm, while the area of a similar triangle measures 31.5 cm2. How much are the sides of the second triangle?

 

[Dr.Peterson]

The sides of a triangle measure 5.2 cm, 8 cm and 8.4 cm, while the area of a similar triangle measures 31.5 cm2. How much are the sides of the second triangle?

Find the area of the first triangle (using Heron's formula or whatever); then use the ratio of the areas to find the ratio of sides.

 

[nasi112]

[MATH]a = 5.2[/MATH][MATH]b = 8[/MATH][MATH]c = 8.4[/MATH]
[MATH]A = \ ?[/MATH][MATH]B = \ ?[/MATH][MATH]C = \ ?[/MATH]
[MATH]x = [/MATH] small area
[MATH]y = [/MATH] big area

[MATH]A = \sqrt{\frac{ya^2}{x}}[/MATH]

 

[LCKurtz]

And remember that the ratio of areas are proportional to the ratio of the squares of the sides.