Plz solve this?

2020-08-07 12:20 pm

回答 (10)

2020-08-07 1:00 pm
Refer to the figure below. Label point E.

A property of triangle: An exterior angle of a triangle is equal to the sum of the opposite interior angles.

∠DBC is an exterior angle of ΔDAB, and the two opposite interior angles are 34° and 30°.
Then, ∠DBC = 34° + 30° = 64°

x is an exterior angle of ΔEBC, and the two opposite interior angles are 64° (∠DBC) and 45°.
Then, x = 64° + 45° = 109°
2020-08-07 10:08 pm
From your figure, we have
<x=<DBC+45*
=>
<x=30*+34*+45*
=>
<x=109*
2020-08-09 11:22 am
I got 109°
To solve it, you just have to remember 2 rules.
1. If you add all 3 angles of a triangle it must equal 180.
2. Any angles that are made with a straight line...or a
straight line with another line running through it forming
2 angles. Well, those 2 angles must add up to 180°

Here's an example of number 2:
2020-08-08 11:06 am
1st solve for Angle B

m∠ABD = 180 - 34 - 30 = 116°

solving for Angle DBC

m∠DBC = 180 - 116 = 64°

next solve the other Angle of smaller triangle Lets call it Angle BEC.

m∠BEC = 180 - 64 - 45 = 71°

And Finally, we solve for x.

x = 180 - m∠BEC = 180 - 71 = 109° Answer//
2020-08-07 3:28 pm
The figure is fooling you, ignore the figure and look just at the data.
The sum of inside degrees of any triangle is always = 180°
The counter-adjacent angle is 180°minus inside degree.

ABD = 180-34-30 = 116°
     X = absolute of (116-180-45) = 109°
2020-08-07 2:37 pm
Some useful things to know: 
Sum of angles in a triangle = 180 degrees
Sum of angles on a line = 180 degrees 
2020-08-07 2:29 pm
180-30-34=116  left side of b.
180-116=64  rt side of b
180-64-45=71
180-71=109=x
2020-08-07 12:28 pm
Whoever drew the picture did a terrible job. It’s 109. 

All interior angles of a triangle is 180 so you can find angle B in ABD. Then you can find angle B in BCX since a straight line is 180. To find angle X in BCX, you use the interior angles of a triangle. Once you find that, you subtract from 180 since a straight line is 180. 
2020-08-07 12:26 pm
angle  DBC is 64° , thus x = 64° + 45° = 109°
2020-08-07 12:28 pm
In the given figure the value of 'x' is 45 + 74 = 109 


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