Let \(P\) be the point (0,5), let Q be the point (6,9), and let R be the point (12,0). Determine the area of right-angled \(\triangle PQR.\)
The right angle is PQR
Note that we can consider PQ to be the base and QR to be the height
PQ = √ [ 6^2 + ( 9 - 5)^2 ] = √ [6^2 + 4^2 ] = √ 52 = 2√13
QR =√ [ (12 - 6)^2 + 9^2 ] = √ [36 + 81 ] = √117 = 3√13
So....the area = (1/2) base * height = (1/2) * (2 √13) * (3√13) = 3*13 units^2 = 39 units^2
Thanks to AZSun for catching my error !!!