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25 votes
25 votes
Given \triangle DEF△DEF triangle, D, E, F, find DE

Round your answer to the nearest hundredth.

User Hassan Yousuf
by
2.9k points

2 Answers

21 votes
21 votes

Answer:

x ≈ 36.09

correct on khan

Explanation:

User Trausti Thor
by
3.4k points
16 votes
16 votes

Answer:

x ≈ 36.09

Explanation:

Complete question

Use △DEF, shown below, to answer the question that follows: Triangle DEF where angle E is a right angle. DE measures x. DF measures 55. Angle D measures 49 degrees. What is the value of x rounded to the nearest hundredth? Type the numeric answer only in the box below.

According to the diagram

m<E = 90 degrees

m<D = 49 degrees

DF = 55 = hypotenuse

DE = x = adjacent

EF = opposite

According to SOH CAH TOA identity;

Cos theta = adj/hyp

Cos m<D = DE/DF

Cos 49 = x/55

x = 55cos49

x = 55(0.6561)

x = 36.0855

x ≈ 36.09 (to the nearest hundredth)

User Ordous
by
2.7k points
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