198,241 views
4 votes
4 votes
Part A-

Which expression can be used for the missing side length of the rectangle? (See picture)

A. x√6
B. 2x
C. x√30
D. 2x√15

Part B-

Find the length of the missing side when x = 3. Round answer to the nearest tenth.

Length = ____ N

User Hanushi
by
2.3k points

1 Answer

15 votes
15 votes

Answer:

Part A: D

Explanation:

Ok Let's assume you are right and the diagonal is 8x. If that is true, one of the answers will work.

Part A

It's the wrong answer. The answer is yes. Use a^2 + b^2 = c^It's the wrong answer. The answer is yes. Use a^2 + b^2 = c^It's the wrong answer. The answer is yes. Use a^2 + b^2 = c^2

givens

diagonal = 8x

one of the legs = 2x.

other leg = ?

Formula

a^2 + b^2 = c^2

(2x)^2 + b^2 = (8x^2) Expand the brackets

4x^2 + b^2 = 64x^2 Subtract 4x^2 from both sides.

b^2 = 64x^2 - 4x^2

b^2 = 60x^2

The prime factors of 60 are 2 * 2 * 3 * 5

You can't do much with the 3 and 5 so leave them under the root sign.

x^2 = x * x

What you get is

b^2 = √3 * 5 * 2* 2 * x * x

The factors come in pairs. One of the pairs goes outs the root. The other one is thrown away.

b = 2*x * √15

So the answer to part A is D

Part B

x = 3

The missing side = 2 * 3 * √15

The missing side = 6√15

The missing side = 23.2

Root 15 = 3.87

User Eric Weiss
by
2.6k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.