Question

The answer is acute I need help with the work

Answer 1

If the 3 sides of a triangle are a, b, c, then

`a^2+b^2Then the triangle is an obtuse angle triangle[tex]a^2+b^2=c^2`

Then the triangle is a right-angled triangle

`a^2+b^2>c^2`

Then the triangle is an acute angled-triangle

Note that c is the longest side

Let us check our sides

`\begin{gathered} \because11^2=121 \\ \because9^2=81 \\ \because8^2=64 \\ \because81+64=145 \end{gathered}`

That means 145 > 121

`\therefore a^2+b^2>c^2`

The triangle is an acute angled-triangle