list all the pairs of congruent angles write the ratio of the corresponding sides in a statement of proportionality find the value of x

Solution
The pair of congruent sides are
[tex]\begin{gathered} PR\cong AC \\ RQ\cong CB \\ PQ\cong AB \end{gathered}[/tex]The ratio of corresponding sides in a statement are
[tex]\frac{PR}{AC}=\frac{RQ}{CB}=\frac{PQ}{AB}[/tex]PQ = 21
AB = x
RQ=24
CB=20
Hence substituting these in x is given as
[tex]\begin{gathered} \frac{24}{20}=\frac{21}{x} \\ 24x\text{ = 21}\times20 \\ x=\frac{420}{24} \\ x\text{ =}17.5 \end{gathered}[/tex]Hence x = 17.5