Question

I need help with an area math question

Answer 1

Answer:

Step-by-step explanation:

Area of outer triangle = $\dfrac{4x*(4x+3)}{2}= 2x*(4x +3)$

                                    = 2x*4x + 2x*3

                                   = 8x² + 6x

Area of inner triangle= $\dfrac{2x*(2x+5)}{2}=x*(2x+5)=x*2x+x*5=2x^{2} + 5x$

Area of aluminium = area of outer triangle - area of inner triangle

                        = 8x² + 6x + 2x² + 5x

                        = 10x² + 11x

Area of 20 aluminum borders = 20*(10x² + 11x)  = 200x² + 220x

b) x = 25 cm

Area of 20 aluminum borders = 200*25² + 220*25

                                                  = 200 * 625 + 220*25

                                                 = 125000  + 5500

                                                  = 130500 cm²

c) Area of inner triangle (Glass) = 5500 cm²

Cost of aluminium = 130500 * 0.06 = $ 7830

Cost of glass = 5500 * 0.03 = $ 165

Cost of making 20 windows =  7830 + 165 = $ 7995