Question

A, B & C form a triangle where

∠BAC = 90°.

AB = 6.6 mm and BC = 17.8 mm.

Find the length of AC, giving your answer rounded to 1 DP.

Answer 1

16.5mm to. 1 decimal place

Explanation:

Please check attachment for diagrammatic representation of the triangle.

Since one of the angles of the triangle is 90, this means that we are dealing with a right angled triangle

To find the length of AC, we make use of pythagoras’ theorem which states that the square of the hypotenuse equals the sum of the square of the other two sides. The hypotenuse is the longest side of the triangle which we have as 17.88 mm

Mathematically therefore

17.8^2 = 6.6^2 + AC^2

AC^2 = 17.8^2 - 6.6^2

AC^2 = 283.28

AC = √(273.28)

AC = 16.53 mm

This is 16.5 to 1 decimal place