, /.,.\ - 



n 



EXERCISES 



1 I tU areas of th following triangles: (I) vertical at the 



'rtioes t t, 0), 



rticm at tho point* < 11. !). r 



80) re ing the formula, and then verify bj substituting in 



the formula. 



2 Prove thai the area of th triangle wboae vertices are at the p. 



I 1 ) U tero, and heuoe that these poinU all lie on 

 the same straight line. 



3 I . the point >, and (3, 9) lie on one straight line? 



'.p. 28.) 



4 ilie points (7, 30), (0, 0), and (-11. 210") lie on one straight 

 line? Solve this by showing that the area of the triangle is iero, and 

 than verify by plotting the figure. 



3. Find the areaof the triangle (*."). (:>*, "), and ( -'.^f"')- 



6. Derive formula [4] when l\ i> in quadrant II, /*, in <|uadraut III, 

 ami /', in quadrant l\ . 



7. Kind the area of the first two triangles in Kx. 1 if the axes make 

 an angle of 60 with each other. 



30. To find the coordinates of the point which divides in 

 a given ratio the straight line from one given point to 

 another. lxt P,=(jr p y,) and P^^(x r y s ) be the two 



points, .P 8 = (r 8 , yj) the required point, ami l-t 



/: 



tin- p.u-ts into which P t divides P\P* ** m i :m t 

 / '. /' a -. P,/' a - ! : my Draw the ordinates M 



