# Singapore Primary School Mathematics - Geometry Part 3 by Education Cube, posted on May 30, 2016

Math Topic – Geometry

Primary 6 Level Question: The figure below is made up of four identical squares of sides 18 cm. Find the area of the figure that is shaded. Can you solve this problem? Scroll down.

When you look carefully, you will understand that the area of the shaded parts is half of the total area of the figure. Here's why:   Concept: Area of the triangle is (½ base X height).

- You will see in all three examples above, the height of the triangle does not change. Hence all three triangles are like the second example, ½ the area of the square.

- If this is a rectangle, and the base of the triangle covers the entire 'length'of the rectangle, then the area of similar triangles are ½ the area of the rectangle. Solution:

Area of shaded part is half the area of the total figure.

Total figure is 18X18X4 = 1,296 square centimeters.

Therefore area of shaded part is 1,296 / 2  = 648 square centimeters.