Question

If Cos θ = 2 √ 10 / 7 calculate the value of Sin θ.

Answer 1

Draw a triangle

Answer 2

I draw a rt triangle, I am not sure of the procedure to solve

Answer 3

Show me your triangle

Answer 4

Use a^2+b^2=c^2

Answer 5

Yes, I tried Pythagoras as 2 sqrt(10) + b^2 = 7^2

Answer 6

\[(2\sqrt{10})^2+b^2=7^2\]

Answer 7

so that gives you:
4(10)+b^2=49

subtract 40:
b^2=9