This is usually used as a proof that triangles have 180°. Look at the attached figures. If you cut off angle A, angle B and angle C and rotate them so that their vertices touch, you form a half-circle out of them (or a straight line). We know that half a circle is 1/2 of 360° or 180; therefore all 3 angles in a triangle must add up to 180°.
Answer:
60
Step-by-step explanation:
(2x+15)=135 They're corresponding angles so they equal/congruent
<u> -15 -15</u> Subtract 15 on both sides since you're looking for x
<u>2x</u> = <u> 120</u> Bring down the remains and subtract 135 from 15
2 2 Add 2 on both sides
x= 60 Divide.
Answer:
yes
Step-by-step explanation:
by the side and letgh
Given:
In a right angle triangle ABC, altitude BD drawn to hypotenuse AC.
AD=3 and, AC=27.
To find:
The length of AB.
Solution:
Draw a figure by using the given information as shown below.
In triangle ABC and ADB,
(Right angles)
(Common angle)
(AA similarity postulate)
We know that the corresponding parts of congruent triangles are proportional. So,

After substituting the given values, we get



Taking square root on both sides, we get


Therefore, the length of AB is 9 units.