(a)[4]
Show that the result is $3r^2+r-6=0$.
(b)[3]
Solve the equation $3r^2+r-6=0$. Give your answer to 2 decimal places, and show all your working.
(c)[2]
Find the square's perimeter.
Mathematics 0580 · IGCSE · Non-right-angled triangles
Non-right-angled triangles — practice question
For this question, every measurement is in centimetres. The diagram depicts a triangle with sides $r+2$ and $r+5$ and a $30^{\circ}$ angle, together with a square of side $r+1$ (NOT TO SCALE). The triangle's area is the same as the square's area.