Question

1 of 6

Given that a = 3.5 cm and b = 9.4 cm, work out the perimeter of the triangle.
Give your answer rounded to 1 DP.
a
b
The diagram is not drawn accurately.

Answer 1

Answer: 23 cm

Explanation:

Given

`a=3.5\ cm\\b=9.4\ cm`

Triangle in the figure is right-angled triangle. Therefore, Pythagoras theorem can be applied. Suppose the unknow length of the triangle is x

`\Rightarrow x^2=a^2+b^2\\\Rightarrow x^2=3.5^2+9.4^2\\\Rightarrow x^2=12.25+88.36\\\Rightarrow x^2=100.61\\\Rightarrow x=10.03\ cm`

The perimeter of triangle is the sum of the lengths of sides.

`\text{Perimeter }P=3.5+9.4+10.03\\\Rightarrow P=22.93\ cm\approx 23\ cm`