Primary 6 · Area · Question type 9.2
A triangle with its base on one side of a rectangle and its tip on the opposite side has half the area of the rectangle.
Already watched the introduction on the chapter page? Try a different question below.
Primary 6, on the MOE Primary Mathematics syllabus.
The lesson · 3 minutes 18 seconds
Watch: a triangle in an 18 cm by 10 cm rectangle, with its tip sliding along the far side
Another worked example
ABCD is a square of side 20 cm. Its diagonals AC and BD are drawn and meet at M. The shaded parts are triangle ABD and triangle ABC. Find the area of the square that is not shaded.
The working · Five lines
Written out in full, the way it should appear on paper.
The answer is 100 cm².
Practise · Modelled on top school exam questions
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Try it yourself
Read the three sections along the rectangle before finding the triangle's area.
ABCD is a rectangle with AB = 30 cm and BC = 12 cm. F and G are points on AB such that AF = 9 cm and GB = 9 cm. E is a point on DC. Find the area of triangle FGE.
Ans: 72 cm²
The practice plan adds more questions and saved progress.
Next, find the visible area after folding the paper. Triangle Area Ratios with Equal Heights →