Topic Details (Notes format)

How to Calculate the Diagonal of a Rectangle

Subject: Mathematics

Book: Maths Mastery

A rectangle’s diagonal forms a right triangle with the length and width. Hence, use the Pythagorean theorem: diagonal d = √(length² + width²). For example, if a rectangle measures 6 m by 8 m, the diagonal is √(6² + 8²) = √(36 + 64) = √100 = 10 m. Diagonal lengths are critical in TV screens or monitor dimensions, tile measurements, and designing rectangular structures. A strong grasp of diagonal formulas ensures you handle “corner-to-corner” distances confidently.

Practice Questions

If x:y = 4:5 and y:z = 2:3, what is x:z?

View Question

If a right triangle has legs of 9 cm and 12 cm, what is the length of the hypotenuse?

View Question

What is the square root of 144?

View Question

What is the slope of a line passing through the points (2, 3) and (4, 7)?

View Question

If 2x - 3 = 7, what is the value of x?

View Question

The sides of a triangle are 7, 24, and 25. Is this a right triangle?

View Question

A number is increased by 20% and then decreased by 10%. What is the net change?

View Question

If 8x = 512, what is the value of x?

View Question

The LCM of 12 and 15 is:

View Question

If the length of a rectangle is doubled and the width is halved, what is the change in area?

View Question