Find the area of the large triangle.

Question

An equilateral triangle has an area of 30 square centimetres. A large triangle is made by increasing each side by a factor of three. Find the area of the large triangle.

Answer 1

When the linear dimensions of a plane figure are multiplied by r, the area of the figure is multiplied by r².

Therefore the larger triangle has an area 3², i.e. nine times the area of the original triangle; Answer = 270 sq. cm.