When you know the length of the three sides of the triangle and not a single angle, the law of sines is of no use. You need to use the law of cosines. In your case, since you want to find angle "C", you use the following;

$c^2=a^2+b^2-2\,a\,b\,cos(C)\\2\,a\,b\,cos(C)=a^2+b^2-c^2\\cos(C)=\frac{a^2+b^2-c^2}{2\,a\,b} \\cos(C)=\frac{16^2+21^2-22^2}{2\,(16)\,(21)}\\cos(C)=0.3169643\\C=arccos(0.3169643)\\C=71.52^o$

4 0

3 years ago

the total cost of 2 kg of Apples in 6 of oranges is rupees 570 if the cost of 3 kg of apples is the same as the cost of 5 kg of

HACTEHA [7]

Answer:

Cost of 1 kg apple = a = RS 102 (Approx.)

Cost of 1 kg orange = b = RS 61 (Approx.)

Step-by-step explanation:

Assume;

Cost of 1 kg apple = a

Cost of 1 kg orange = b

So,

2a + 6b = 570 ....... Eq1

and

3a = 5b..........Eq2

From eq 2

3a = 5b

a = 5b / 3

So,

2a + 6b = 570

2(5b/3) + 6b = 570

b = 61.07

Cost of 1 kg orange = b = RS 61 (Approx.)

a = 5b / 3

a = 5(61) / 3

Cost of 1 kg apple = a = RS 102 (Approx.)

7 0

3 years ago

The ratio of boys to girls in a class is 4:5 what fraction of teh class are boys

GalinKa [24]

Answer:

4/9

Step-by-step explanation:

If you add the ratios, it gives you the total, so 4 + 5 = 9. 9 total students. Since boys is represented by 4, then 4/9 is the fraction for boys and 5/9 is the fraction for girls.

5 0

3 years ago

Read 2 more answers

What's 5 plus 5<br>A:10<br>B:14<br>C:93

AleksandrR [38]

Idk if this is serious... but 10....

8 0

3 years ago

Read 2 more answers