Triangle rst was dilated by a scale factor of 1/2. the image, triangle r's't', is an isosceles triangle, with each leg measuring 8 units. what is the length of a leg of the pre-image, triangle rst?

Triangle RST was dilated by a scale factor of 1/2
Given: triangle R'S'T', is an isosceles triangle, with each leg measuring 8 units. 
Pre-image: measure of pre-image * scale factor = measure of resulting image
measure of pre-image = measure of resulting image / scale factor
measure of pre-image = 8 / 1/2measure of pre-image = 8 * 2/1 
measure of pre-image = 16 units.