For this question we need to utilise Pythagoras theorem. Pythagoras theorem states that a² + b² = c² so the sum of the leg's squared will equal the hypotenuse squared. In this question we are given the hypotenuse so we will have to rearrange the equation to find the value of the leg,
→ a² + b² = c²
⇒ Substitute in the values
→ 20² + b² = 30²
⇒ Simplify
→ 400 + b² = 900
⇒ Minus 400 from both sides to isolate b²
→ b² = 500
⇒ Square root both sides to find the value of the leg
→ b = 22.360679775 cm
The length of the missing leg is 22.36 cm to nearest hundredth considering one leg is 20 cm and the hypotenuse is 30 cm.
