Area of a polygon and support problems
Answers are for parents and teachers.
1
A hexagon is split into 4 triangles of areas 3, 4, 5 and 6. What is its area?
18
2
A 6 × 5 part is removed from a 15 × 10 rectangle. What is the area of the rest?
120
3
In a trapezoid the diagonals meet at O, S(AOB) = 14, S(BOC) = 7. Find S(AOD) (use S(AOB) = S(COD) and the first support problem).
28
4
A parallelogram has base 16 cm and altitude 5 cm. What is the area (cm²) of a triangle with that base and altitude?
40
5
Explain in your own words how to find the area of a pentagon.
Split it into triangles with the diagonals from one vertex and add their areas.