Step 1: Analyze △PQS.
Given ∠PQS=45∘ and ∠QPS=45∘.
The sum of angles in a triangle is 180∘.
∠PSQ=180∘−∠PQS−∠QPS
∠PSQ=180∘−45∘−45∘
∠PSQ=90∘
This confirms that PS is perpendicular to QR.
Step 2: Analyze △PRS.
Since PS⊥QR, we have ∠PSR=90∘.
We are given ∠PRT=30∘. Note that ∠PRT is the same as ∠PRS.
So, in right-angled △PRS:
∠RPS=180∘−∠PSR−∠PRS
∠RPS=180∘−90∘−30∘
∠RPS=60∘
Step 3: Calculate ∠SPT.
From the diagram, point T lies on the line segment SR. Therefore, ∠RPS is the sum of ∠RPT and ∠SPT.
∠RPS=∠RPT+∠SPT
We know ∠RPS=60∘ (from Step 2) and we are given ∠RPT=30∘.
60∘=30∘+∠SPT
∠SPT=60∘−30∘
∠SPT=30∘
The value QS=4.5 cm is not required to solve for ∠SPT.
The final answer is 30∘.