The diagram below shows an equilateral triangle ABC with AB = (4x - 9)cm. Diagram not drawn to scale
В B.
Α'
(4x – 9) cm
The perimeter of the triangle is 45 cm.
Calculate the value of x.
[3]
+

1. ∠1 is complementary to ∠2 and ∠3 is complementary to ∠2. subtraction property of equality 2. m∠1 + m∠2 = 90 and m∠3 + m∠2 = 90 substitution 3. m∠1 + m∠2 = m∠3 + m∠2 definition of complementary 4. m∠1 = m∠3 given