Mathematics:
In a triangle ABC are (BC)=2(AB) and (AC)=5/2(AB)
a.) Find cos c
b.) Find the area of the triangle ABC expressed by c
Again good luck 😀
between the Næstved Gymnasium in Denmark and the LP2I in France
Mathematics:
In a triangle ABC are (BC)=2(AB) and (AC)=5/2(AB)
a.) Find cos c
b.) Find the area of the triangle ABC expressed by c
Again good luck 😀
Posted in Group8.
– 20 May 2009
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I imagine the triangle ABC is a right triangle, isn’t it ???
thank you
1) When we use the theoreme of Al-Kashi, we find :
x²=(2x)²+(5/2x)²-2*2x*5)2x*cos ACB(angle)
…
x²=1x²/4*cos ACB
x²/(x²/4)= cos ACB
x²*4/x²= cos ACB
4x²/x²= cos ACB
4= cos ACB
So the cosinus of c is 4.
2)
The formule for find the aera of a triangle is (b*h)/2
so in this triangle is (5/2(AB)*cosC)*h/2 (but we are not sure)