In the given figure, AB∥DC and AD∥BC.
Also, ∠ADC=(2x+5)∘ and ∠BCD=(3x+55)∘. Find the measure of x.
(3 marks)
AB∥DC and AD∥BC
∠ADC+∠BCD=180∘ (Sum of Co−interior angles)
⇒ (2x+5∘)+(3x+55∘)=180∘
(1 mark)
= (2x+3x)+(5∘+55∘)=180∘
= (5x)+(60∘)=180∘
= 5x=180∘−60∘
= 5x=120∘
=> x=24∘
(2 marks)