Answer :

Answer:

Blank 1:  20

Blank 2: 43.6

Step-by-step explanation:

Question 1

To find the length of leg PQ in right triangle PQR, we can use the Pythagorean Theorem:

[tex]\boxed{\begin{array}{l}\underline{\textsf{Pythagorean Theorem}}\\\\a^2+b^2=c^2\\\\\textsf{where:}\\\phantom{ww}\bullet\;\textsf{$a$ and $b$ are the legs of the right triangle.}\\\phantom{ww}\bullet\;\textsf{$c$ is the hypotenuse (longest side) of the right triangle.}\\\end{array}}[/tex]

In this case:

  • a = PQ
  • b = QR = 21 cm
  • c = PR = 29 cm

Substitute the values into the formula and solve for PQ:

[tex]PQ^2+QR^2=PR^2\\\\PQ^2+21^2=29^2\\\\PQ^2+441=841\\\\PQ^2=841-441\\\\PQ^2=400\\\\PQ=\sqrt{400}\\\\PQ=20[/tex]

Therefore, the measure of side PQ is:

[tex]\LARGE\boxed{\boxed{PQ=20\; \sf cm}}[/tex]

[tex]\dotfill[/tex]

Question 2

To find the measure of angle R, we can use the cosine trigonometric ratio:

[tex]\boxed{\begin{array}{l}\underline{\textsf{Cosine trigonometric ratio}}\\\\\sf \cos(\theta)=\dfrac{A}{H}\\\\\textsf{where:}\\\phantom{ww}\bullet\;\textsf{$\theta$ is the angle.}\\\phantom{ww}\bullet\;\textsf{$A$ is the side adjacent the angle.}\\\phantom{ww}\bullet\;\textsf{$H$ is the hypotenuse (the side opposite the right angle).}\end{array}}[/tex]

In this case:

  • θ = R
  • A = QR = 21
  • H = PR = 29

Substitute the values into the formula and solve for R:

[tex]\cos R=\dfrac{21}{29}\\\\\\R=\cos^{-1}\left(\dfrac{21}{29}\right)\\\\\\R=43.6028189727...\\\\\\R=43.6^{\circ}\; \sf (nearest\;tenth)[/tex]

Therefore, the measure of angle R rounded to the nearest tenth is:

[tex]\LARGE\boxed{\boxed{R=43.6^{\circ}}}[/tex]