Question

1) triunghi ABC dr. (A = 90°)

AC=20 cm
AB= 15 cm

a) P, A triunghi

b) sui. B. sui. c
cos.B , tg . c​

Answer 1

Explicație pas cu pas:

T. Pitagora

${bc}^{2} = {ab}^{2} + {ac}^{2}$

${bc}^{2} = {20}^{2} + {15}^{2}$

${bc}^{2} = 400 + 225 = 625$

$bc = \sqrt{625} = \sqrt{ {25}^{2} } = 25$

$p = ab + ac + bc = 20 + 15 + 25 = 60$

$a = (ac \times ab ) \div 2 = 20 \times 15 \div 2 = 150$

b)

$\sin(b) = \frac{ac}{bc} = \frac{20}{25} = \frac{4}{5}$

$\sin(c) = \frac{ab}{bc} = \frac{15}{25} = \frac{3}{5}$

$\cos(b) = \frac{ab}{bc} = \frac{15}{25} = \frac{3}{5}$

$\tan(c) = \frac{ab}{ac} = \frac{15}{20} = \frac{3}{4}$