waecmaths question:
The angles of a triangle are (x +10)o, (2x – 40)o and (3x – 90)o. Which of the following accurately described the triangle
Option A:
It is a scalene triangle
Option B:
It is a right angles isosceles triangle
Option C:
It is an equilateral triangle
Option D:
It is an isosceles triangle but not right angled
waecmaths solution:
$\begin{align} & {{(x+10)}^{\circ }}+{{(2x-40)}^{\circ }}+{{(3x-90)}^{\circ }}={{180}^{\circ }} \\ & {{(6x-120)}^{\circ }}={{180}^{\circ }} \\ & 6x=300 \\ & x=50 \\\end{align}$Substituting x = 50o into the values, show that the triangle is an equilateral triangle.
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