In the figure above, what is the length of ?
A. 8
B. 9
C. 12
D. 15
Answer:C
In the figure above, what is the length of ?
A. 8 B. 9 C. 12 D. 15
Explanation: CThe 5 equal lengths that make up the two sides of the largest triangle tell us that we are dealing with 5 similar triangles. The largest triangle has sides 15:25:30, and the sides of all 5 triangles will have an equivalent ratio. Reduced, the ratio is 3:5:6, which happens to be the dimensions of the smallest triangle. We want to find the length of BD, the base of a triangle with sides of 6 and 10. This is twice as big as the smallest triangle, so the base BD must be 6 × 2 =12, which is (C).