Answer:
Step-by-step explanation:
Supongamos que tenemos un triángulo rectángulo cuya hipotenusa es de 3 cm y su ángulo es de 70 °.
Entonces; digamos que el triángulo rectángulo es un triángulo ABC;
dónde;
∠A =90°
∠B = 70°
∠C = ???
∴
∠A + ∠B + ∠C = 180°
90° + 70° + ∠C = 180°
160° + ∠C = 180°
∠C = 180° - 160°
∠C = 20°
Usando la regla de trigonometría;
![cos \theta = (adjacent)/(hypotenuse)](https://img.qammunity.org/2022/formulas/spanish/high-school/tdu4n6gfmp4bahb4u55nwtqzhc52gmmdw2.png)
![Cos (70^0) = (c)/(3)](https://img.qammunity.org/2022/formulas/spanish/high-school/sipxzv2gqhybhydzvnlvirj8hklbep2ial.png)
![c=0.342 *3\\](https://img.qammunity.org/2022/formulas/spanish/high-school/rz4kk43kn8428xivhdm1er0dueaaw8eg4y.png)
![c = 1.03\\](https://img.qammunity.org/2022/formulas/spanish/high-school/tx6yb3p2e63wp4abzrxiycow98r4w1dqj1.png)
Usando la regla de Pitágoras;
a² = b² + c²
3² = b² + 1.03²
9 = b² + 1.06
9 - 1.06 = b²
7.94 = b²
![b = √(7.94)](https://img.qammunity.org/2022/formulas/spanish/high-school/1asvcfk7cdqz9zun517tkkznoo25rfvjid.png)
b = 2.82