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PLEASE HELP ME TO ANSWER THIS QUESTION.

A right pyramid PQRST has a rectangular base QRST. Given
that W is the midpoint of QS and RT, the lengths of QT = 8 cm,
TS = 6 cm and point P is vertically above point W, calculate
(a) PT, in cm, if PW = 12 cm
(b) the value of < PTR [angle PTR]

THANK YOU!!!​

PLEASE HELP ME TO ANSWER THIS QUESTION A right pyramid PQRST has a rectangular base QRST Giventhat W is the midpoint of QS and RT the lengths of QT 8 cmTS 6 cm class=

Respuesta :

Answer:

(a) PT = 13 cm

(b) <PTR = [tex]39.7^{o}[/tex]

Step-by-step explanation:

(a) Applying the Pythagoras theorem to QST, we have;

[tex]QS^{2}[/tex] = [tex]ST^{2}[/tex] + [tex]QT^{2}[/tex]

      = [tex]6^{2}[/tex] + [tex]8^{2}[/tex]

[tex]QS^{2}[/tex] = 36 + 64

       100

QS = [tex]\sqrt{100}[/tex]

     = 10

QS = 10 cm

Since QS = TR, then;

WT = [tex]\frac{1}{2}[/tex] TR

      = [tex]\frac{1}{2}[/tex] x 10

WT = 5 cm

Thus, applying Pathagoras theorem to PWT;

[tex]PT^{2}[/tex] = [tex]PW^{2}[/tex] + [tex]WT^{2}[/tex]

      = [tex]12^{2}[/tex] + [tex]5^{2}[/tex]

      = 144 + 25

[tex]PT^{2}[/tex] = 169

PT = [tex]\sqrt{169}[/tex]

    = 13

PT = 13 cm

(b) To determine <PTR, TR = 10 cm. Apply the required trigonometric function;

Cos θ = [tex]\frac{adjacent}{hypotenuse}[/tex]

Cos θ = [tex]\frac{10}{13}[/tex]

          = 0.7692

θ = [tex]Cos^{-1}[/tex] 0.7692

  = 39.7179

θ = [tex]39.7^{o}[/tex]

Therefore, <PTR = [tex]39.7^{o}[/tex]