Question

Use ABC, in which AB = 48, AC = 64, and BC = 80, to answer the question.

Answer 1

Answer:

$CosB = \frac{48}{80}$

Step-by-step explanation:

Given

AB = 48, AC = 64, and BC = 80

Required

Determine the ratio of cosB

The first step is to determine, which type of triangle it is.

Checking for Right Angled Triangle

For a triangle to be a right angled triangle, the square of the largest side must be equal to the sum of squares of other sides

This implies that:

$80^2 = 48^2 + 64^2$

$6400 = 2304 + 4096$

$6400 = 6400$

Hence, the triangle is a right angled triangle [See attachment]

From trigonometry;

$CosB = \frac{Adjacent}{Hypotenuse}$

The adjacent of B = 48 while the hypotenuse is 80;

Hence;

$CosB = \frac{48}{80}$

Hence, the ratio of cos B is $CosB = \frac{48}{80}$