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Find angle abc (2x+14) (x+7)

2 Answers

3 votes
Angles represented by 2x+14 and x+7 must add up to 90 degrees. Thus,

2x+14 + x+7 = 90, so that

3x + 21 = 90, or 3x = 69, or x = 23.

Then angle ABC is x+7, or 23+7, or 30 degrees.

If that's the case, then angle CBD must be 60 degrees. Is it?
Subst. 23 for x in 2x+14: 2(23)+14 =46+14 = 60 (degrees). YES.


User Nkadwa
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6.4k points
1 vote
It's a complementary angle, so just solve for x and subtract the CBD from 90,
First, we have to solve for x.
2x + 14 + x + 7 = 90
Combine like terms
3x + 21 = 90
Balance, subtract 21 from each side.
3x = 69
Divide 3 from each side
x = 23.
So know that we know x is 23, we can go about it 2 ways, subtracting the other angle with 90 or just substituting the variable, I'd just substitute the variable for it so just do 23 + 7. That equals 30, angle ABC = 30.


User Deanmcpherson
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6.5k points