Answer: For first box - (x)°+(3x)°+(5x)°= 180°
For second box - x=20
Step-by-step explanation:
According to the given picture :-
We have ΔPQR having ∠P=(x)°, ∠Q= (3x)° and ∠R=(5x)°. (i)
To prove : x= 20
The angle sum property of triangle says that the total sum of all i terior angles of a triangle is 180°.
i.e. For ΔPQR
∠P+∠Q+∠R= 180° (ii)
Using substitution property , Substitute the values of ∠P, ∠Q and ∠R from (i) in (ii), we get
(x)°+(3x)°+(5x)°= 180°
⇒x+3x+5x=180 [Simplify]
⇒9x=180
Using division property of equality , divide both sides by 9 , we get\
x=20
hence, the completed proof is given below .
