Question

A is an acute angle in a right triangle, Given that Sin A= 7/25, what is the ratio for Cos A? Enter your answer in the box as a fraction in simplest form.

Answer 1

$\sin \theta = \dfrac{opp}{hyp}$

$\sin A = \dfrac{7}{25} = \dfrac{opp}{hyp}$

$a^2 + b^2 = c^2$

$a^2 + 7^2 = 25^2$

$a^2 = 625 - 49$

$a = \sqrt{576}$

$a = 24$

$adj = a = 24$

$\cos A = \dfrac{adj}{hyp}$

$\cos A = \dfrac{24}{25}$

Answer 2

Find the adjacent side of the triangle ... 
7² + x² = 25²
x² = 25² - 7²
x² = 576
x = 24 
The adjacent side of the triangle is 24

Given that sin A = $\frac{7}{25}$
Since sin A = $\frac{o}{h}$
We can conclude that o = 7 and h = 25

cos A = $\frac{a}{h}$
cos A = $\frac{24}{25}$