In construction and civil engineering & any other areas, we often deal with irregular shapes while preparing drawings or taking site measurements etc. One such common case is when a rectangular area is trimmed by a diagonal cut, creating a slanted side.
In this article, we will find it out how to calculate the slanted side of the figure shown the image

Given Dimensions From the image

• Left vertical side = 9 m
• Bottom horizontal side = 8 m
• Top horizontal side = 5 m
• Right vertical side (below chamfer) = 5 m
• Slanted side = c (to be calculated)

The figure can be visualized as a rectangle where the top-right corner is cut off by a diagonal line.

Step 1: Identify the right-angled triangle

From the image:

Bottom Horizontal length is 8m & Top Horizontal length is 5m
So, a = 8 – 5 = 3 m

Left Vertical side is 9m & Right Vertical Side is 5m
So. b = 9 -5 = 4m

This forms a right-angled triangle with:

• a = 3m
• b = 4m
• Hypotenuse = c (the slanted side we need).

Step 2: Apply Pythagoras Theorem

The Pythagoras theorem states:

a² + b² = c²

3² + 4² = c² , c² = 9+ 16 ,

c² = 25, c = √25

c = 5 m, The length of the slanted side is: c = 5m ​

Practical Application

This simple method of applying the Pythagoras theorem is widely used in:

• Construction site layout – to calculate diagonal cuts.
• Structural drawings – to determine true lengths of slanted edges.
• Quantity surveying – to calculate accurate lengths of members for estimation.