Question

The hypotenuse, c, of right triangle ABC is 5.0 cm long. Give the trigonometry ratio cosA=0.50 for angle A, what is the area of the triangle to the nearest tenth of a cm?

Answer 1

CosA = , so <A is 60º

Hypotenuse (c) is 5

Opposite is (b)

Adjascent is (a)

cos A = -----> ---------> a =

Pytagoras

A = b . a . 1/2

A =

Explanation:

Answer 2

`(25√(3) )/(8)`

Explanation:

CosA =
`(1)/(2)` , so <A is 60º

Hypotenuse (c) is 5

Opposite is (b)

Adjascent is (a)

cos A =
`(adjascent)/(hypotenuse)` ----->
`(1)/(2) = (a)/(5)` ---------> a =
`(5)/(2)`

Pytagoras

`5^(2) = ((5)/(2)) ^(2) + b^(2)\\ b^(2) = 25 - (25)/(4) \\b^(2) = (75)/(4) \\\\b = (5√(3) )/(2)`

A = b . a . 1/2

A =
`(25√(3) )/(8)`