1)If Sin θ = 4/5 , What is the value of Cos θ
3/5
Sin θ = P/H = 4/5 ;
By Pythagoras Theorem: –
\( {P^2 + B^2 = H^2}\) ;
B = 3 ;
Cos θ = B/H = 3/5;
2)If tan θ = 3/4 , what is the value of Cosec θ
5/3
tan θ = P/B = 3/4 ;
By Pythagoras Theorem: –> H = 5 ;
Cosecθ = H/P = 5/3
3)If length of three sides of tringle AB, BC & AC are 2cm, 3cm & 4cm respectively, then the value of cos A is
11/16
applying Cosine Law, we get::
\(cos A = {4^2 +2^2 -3^2 \over 2 \times 2 \times 4} = {11 \over 16}\)
4)If three sides of triangle with sides AB, BC and AC are 3cm, 3cm and 4cm respectively then, what is the value of \( {sinA \over sinB}\)?
3/4
sin law \({a\over sin\space A}={b\over sin\space B}= {c\over sin\space C}\) ;
\({3 \over sinA} = {4 \over sinB}\) ; \({sinA \over sinB} = {3 \over 4} \)
5)If in a triangle, value of length of two sides are 4cm, 5cm & angle between them is 60°, then what is the length of third side (in cm)
√21
Let third side be x cm
\(cos60^0 = {4^2 +5^2 -x^2 \over 2 \times 4\times 5} \) ; solving we get
x = √21