Answer:
x = 13
39° and 51°
Step-by-step explanation:
Angles in a triangle add up to 180 degrees.
This is a right angle triangle, so one side has a size of 90 degrees.
3x + 4x - 1 + 90 = 180
7x + 89 = 180
7x = 91
x = 91/7
x = 13
Put x as 13 to work out the size of the angles.
3(13) = 39
4(13) - 1
52 - 1 = 51
<u>Let's consider the facts at hand</u>:
- By Vertical Angle Theorem ⇒ ∠BCE = ∠DCF
- ∠BEC = ∠DFC
- Sides BE = DF
<u>Based on the diagram, triangles BCE and triangles DCF are similar</u>
⇒ based on the Angle-Angle theorem
⇒ since ∠BCE = ∠DCF and ∠BEC = ∠DFC
⇒ the two triangles are similar
Hope that helps!
<em>Definitions of Theorem I used:</em>
- <u><em>Vertical Angle Theorem: </em></u><em>opposite angles of two intersecting lines must be equal</em>
- <u><em>Angle-Angle Theorem:</em></u><em> if two angles of both triangles are equal, then the given triangles must be similar</em>
<em />
If x is negative, then 10-x must be positive.
for example: let's say x=-1. then 10-(-1)=11
