Answer:
Final answer is m∠D = 61°.
Step-by-step explanation:
Given that m∠C = 98°,
m∠B = 140°,
m∠A = m∠D ,
Using those information we need to find the value of m∠D.
We know that sum of all 4 interior angles of a quadrilateral is always 360°.
So we can write equation:
m∠A +m∠B +m∠C +m∠D = 360°
m∠A + 140° + 98° +m∠D = 360°
m∠D + 140° + 98° +m∠D = 360°
2(m∠D) + 140° + 98° = 360°
2(m∠D) + 238° = 360°
2(m∠D) = 360° - 238°
2(m∠D) = 122°
m∠D = 122°/2
m∠D = 61°
Hene final answer is m∠D = 61°.
