Question

Find the measure of the largest angle in ABC if a = 12, b = 8 and c = 13.

Answer 1

Answer:

$C=78.28^{\circ \:}$

Step-by-step explanation:

We are given a triangle

whose sides are

a=12

b=8

c=13

Since, c is largest among them

So, angle C must be largest angle

we can find angle C

we can use law of cosine formula

$cos(C)=\frac{a^2+b^2-c^2}{2ab}$

now, we can plug values

$cos(C)=\frac{12^2+8^2-13^2}{2\times 12\times 8}$

$cos(C)=\frac{13}{64}$

now, we can find angle

we get

$C=78.28^{\circ \:}$