Nanyang Pri Sch P6 CA1 2008 Math 46

The figure below is made up of a rectangle, square and a shaded triangle. Find the area of the shaded triangle.



Solution



Area of Triangle A ----- ½ x 1cm x 6 cm = 3 square cm
Area of Rectangle B ----- 4cm x 1cm = 4 square cm
Area of Triangle C ----- ½ x 7cm x 4cm = 14 square cm

Area of A + B + C + shaded triangle -----
½ x 8cm x 10cm = 40 square cm

Area of shaded triangle -----
(40 – 14 – 4 – 3) square cm = 19 square cm (Answer)