The angles of triangle are x 10 o 2x - 40 o and... - WAEC Mathematics 2009 Question

The angles of triangle are (x + 10)^o, (2x - 40)^o and (3x - 90)^o. Which of the following accurately describes the triangle?

it is a scalene triangle

it is right angled isosceles triangle

t is an equilateral triangle

It is an isosceles triangle but not right angled

correct option: c

(x + 10)^o + (2x - 40)^o + (3x - 90)^o = 180

6x - 120 = 180

6x = 180 + 120

6x = 300

x = \(\frac{300}{6}\)

x = 50

x + 10^o = 50^o + 10^o = 60^o

2x - 40 = 2(50^o) - 40 = 60^o

3x - 90 = 3(50^o) - 90^o = 60^o

Hence, it is an equilateral triangle

Please share this, thanks: