2 Answers

Sofeda · Answer 1 · 2020-07-16T02:37:51+0000

Answer:

cosine∠R = 1/2

Explanation:

We have to find the figure of triangle.

We have to find the cosine∠R.

First we find the base of triangle.

We have formula: Hypotenuse² = Base² + perpendicular²

Hypotenuse = 20

Base= ?

perpendicular = 10√3

Applying formula we get,

Base = √20² - (10√3)²

base = 10

As we know that :

cosФ = base/hypotenuse

cosine∠R = 10/20

cosine∠R = 1/2 is the result.

Jacob CUI · Answer 2 · 2020-07-17T22:00:34+0000

Hello!

The answer is:

cos(R)=(1)/(2)

Since it's a right triangle and we need to know the adjacent side of the triangle, in order to find cos(R), we can use the Pythagorean Theorem.

Pythagorean Theorem formula:

c^(2)=a^(2) +b^(2)

Where:

$c=hypotenuse=20\\a=FirstTriangleSide=AdjacentSide\\b=SecondTriangleSide=OppositeSide=10√(3)$

So, the adjacent side will be:

$AdjacentSide=\sqrt{c^(2)-b^(2)}=\sqrt{20^(2)-(10√(3))^(2)}=√(400-100*3) \\AdjacentSide=√(100)=10$

Now, that we know the adjacent side, we can calculate cos(R), so:

cos(R)=(AdjacentSide)/(Hypotenuse)=(10)/(20)=(1)/(2)

Have a nice day!