Question 91544
Altitude of the triangle = 13 m
Base of the triangle = 25 m

Area = (1/2)*base*altitude
     = (1/2)*25*13

     = 162.5 sq m

Cost of sheet metal /sq m = $4.5

So cost of sheet to make the triangle = 162.5 x 4.5

                                      = $731.25

Good Luck