Question

Answer please please I cant think

Answer 1

Answer: ∠A = 20°; ∠B = 59°; ∠C = 101°

Step-by-step explanation:

According to the problem:

• ∠A = ∠A
• ∠B = 4 · ∠A - 21°
• ∠C = 5 · ∠A + 1°

All interior angles within a triangle adds up to 180°:

∠A + ∠B + ∠C = 180°

$A+(4A-21)+(5A+1)=180\\\\A+4A+5A-21+1=180\\\\10A=180+21-1\\\\10A=200\\\\A=20\°$

Substitute in the value of ∠A into the other equations:

∠B = 4 · ∠A - 21° = 4(20°) - 21° = 80° - 21° = 59°

∠C = 5 · ∠A + 1° = 5(20°) + 1° = 100° + 1° = 101°