Hello,

I hope you can help me solve this question.

A triangle has sides of length 4, 5, 7 units. Find, to the nearest tenth of a degree, the size of the largest angle.

Thanks.

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- Nov 29th 2008, 01:27 PMAminekhadirTriangle Units
Hello,

I hope you can help me solve this question.

A triangle has sides of length 4, 5, 7 units. Find, to the nearest tenth of a degree, the size of the largest angle.

Thanks. - Nov 29th 2008, 01:33 PMrunning-gag
Hi

You can use the cosines formula

a,b,c being the lengths of the sides of a triangle

A,B,C being the angles (A is the angle formed with sides whose length are b anc c (opposite to the length a))

a²=b²+c²-2bc cosA

Then cosA=(b²+c²-a²)/(2bc) - Nov 29th 2008, 01:45 PMAminekhadir
Thanks :)