1. Construct the Isosceles triangle from given data below : Altitude = 55mm Perimeter = 135mm

  base: 22 37/54; sides: 56 17/108

Step-by-step explanation:

If we let x represent half the length of the base, and y represent the length of the side, then we have ...

  2x +2y = 135 . . . . . perimeter relation

  x^2 +55^2 = y^2 . . . . Pythagorean theorem relation

Solving for y and substituting into the second equation, we have ...

  y = 135/2 -x

  x^2 + 3025 = (67.5 -x)^2

  3025 = -135x +4556.25 . . . . . . expand, subtract x^2

  135x = 1531.25 . . . . . . . . . . add 135x -3025

  x = 1531.25/135 = 11 37/108

The length of the base is double this value, 22 37/54.

The length of each side is 67.5 -11 37/108 = 56 17/108.

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Check

The perimeter is the base plus two side lengths:

  22 37/54 + 2(56 17/108) = (22 +112) +37/54 +17/54 = 134 +1 = 135.

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2