Question

In ∆ABC, right angled at B, AB = 24cm, BC = 7cm. Determine

(I)sinA, cosA [ angle at A]

(II)sinC, cosC [ angle at C]

Answer 1

In ∆ ABC 
B =90° 

AB = 24 cm
BC = 7cm 
Therefore hypotenuse AC will be 
√24²+7²
= √576+49
=√ 625
=25cm

SinA = BC/AC
= 7/25 
Cos A= AB/AC
= 24/25

sinC = AB/AC
= 24/25
CosC = BC/AC
= 7/25

Answer 2

Answer:

Angle B is 90°

So By Pythagoras theorem,

$AC^{2} =AB^{2}+ BC^{2} \\AC^{2} =24^{2} +7^{2} \\AC^{2} =576+49\\AC^{2} =625\\AC=\sqrt{625} \\AC=25 cm$

sinA= BC÷AC

       =7/25

cosA= AB÷AC

        =24/25

sinC = AB÷AC

        =24/25

cosC= BC÷ AC

        =7/25