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Please help i’ve been stuck on this problem for some time

Please help i’ve been stuck on this problem for some time-example-1
User Sunghun
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1 Answer

3 votes

ANSWER

m∠T = 58°

Step-by-step explanation

If the two triangles are congruent, then their corresponding angles are congruent - and therefore their measures are the same:


\begin{gathered} m\angle A=m\angle S \\ m\angle B=m\angle T \\ m\angle C=m\angle U \end{gathered}

So the measure of angle T is the same as the measure of angle B. We have to find the value of x first.

The sum of the measures of the interior angles of any triangle is 180°. So we have for the second triangle:


m\angle S+m\angle T+m\angle U=180\degree

Remember that the measure of angle T is the same as angle B's. Replace with the expressions for the angle's measures:


(4x+12)+(5x-27)+(3x-9)=180

Add like terms:


\begin{gathered} (4x+5x+3x)+(12-27-9)=180 \\ 12x-24=180 \end{gathered}

Solve for x. Add 24 to both sides of the equation:


\begin{gathered} 12x-24+24=180+24 \\ 12x=104 \end{gathered}

And divide both sides by 12:


\begin{gathered} (12x)/(12)=(204)/(12) \\ x=17 \end{gathered}

Now we replace x = 17 into the expression for angle's T measure and solve:


\begin{gathered} m\angle T=m\angle B=5x-27 \\ m\angle T=5\cdot17-27 \\ m\angle T=85-27 \\ m\angle T=58\degree \end{gathered}

User Kousuke Ariga
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