Question

The triangles are similar. The area of the larger triangle 603cm2. what is the area of the smaller triangle?

small triangle: 18cm
large triangle: 54cm

A. 10.5cm2
B. 31.5cm2
C. 67cm2
D. 189cm2

Answer 1

The smaller triangle is scaled by a factor of (18 cm)/(54 cm) = 1/3 of the larger triangle. The ratio of areas is the square of that scale factor.

small triangle area = (1/3)^2 × large triangle area

... = (1/9) × 603 cm^2

... = 67 cm^2

The appropriate choice is

... C. 67 cm^2