In the adjoining figure, ABC is a triangle right angled at C. A line segment through the mid-point M of AB and parallel to BC intersects AC at D. Show that CM = 12 AB.
Open in App
Solution
In △ABC,
M is the mid-point of AB and MD∥BC
∴D is the mid-point of AC
In △AMD and △CMD
AD=CD since D is the mid-point of AC
∠ADM=∠CDM as MD⊥AC
DM=DM (common)
∴△AMD≅△CMD by SAS congruence rule
∴AM=CM by CPCT .........(1)
However,AM=12AB since M is the mid-point of AB .........(2)