Isosceles 7929

ABCD isosceles trapezoid. A = 6cm, e = 7cm and delta angle = 105 °. Calculate the remaining pages.

Correct answer:

b =  5.4788 cm
c =  3.164 cm
d =  5.4788 cm

Step-by-step explanation:

a=6 cm e=7 cm D=105   B=180D=180105=75   e2 = a2 + b2  2ab cos B  72 = 62 +x2  2 6 x cos (75°)  x23.106 x13=0  x23.106 x13=0 x23.106x13=0  a=1;b=3.106;c=13 D=b24ac=3.106241(13)=61.647236 D>0  x1,2=2ab±D=23.11±61.65 x1,2=1.553±3.925788 x1=5.478787692 x2=2.372787692  b=x1=5.4788=5.4788 cm

Our quadratic equation calculator calculates it.

cos B = x/b x=b cos(B)=5.4788 cos(75°)1.418 cm c=a2 x=62 1.418=3.164 cm
d=b=5.4788=5.4788 cm

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Calculation of an isosceles triangle.
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Cosine rule uses trigonometric SAS triangle calculator.
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