Example for Intermediate and Higher tier
This an example of using ratio and proportion and is discussed further in Similar shapes.
The following two triangles are similar. Find the lengths p and q to one decimal place.
Solution
First find the ratio by comparing two of the same sides in the similar triangles:
16.5 ÷ 6.6 = 2.5
This means that going from the small to big triangle, we have to multiply by 2.5.
And going from the big triangle to the small one we have to divide by 2.5.
Therefore:
q = 4.8 × 2.5 = 12.0 cm
p = 14.5 ÷ 2.5 = 5.8 cm
