PK 2016 Q12
12. The large triangle shown has sides of length 5 units. What percentage of the area of the triangle is shaded?
- A 80%
- B 85%
- C 88%
- D 90%
- E impossible to determine

Pink Kangaroo 2016, Question 12. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: C 88%
By dissecting the triangle into smaller, identical triangles, we see that the shaded area is 22/25 of the larger triangle, which corresponds to 88/100 = 88%.

Solution © UK Mathematics Trust, from the PK 2016 solutions.