Answer:
a) 7x + 48 = 90 which simplifies to 7x = 42
b) m∠B = 35°m m∠C = 90°, m∠D = 55°
Explanation:
The three angles of a triangle add up to 180°
Therefore the sum of the measures of angles B, C and D should be 180
==> m∠B + m∠C + m∠d = 180
Since m∠C = 90,
m∠B + 90 + m∠D = 180
m∠B + m∠D = 180 - 90 = 90
Since m∠B = (2x+43)° and m∠D = (5x+5)°.
(2x + 43) + (5x + 5) = 90
==> 7x + 48 = 90
==> 7x = 90 - 48 = 42
==> x = 42/7 = 6
b)
m∠B = 5 x 6 + 5 = 35°
m∠C = 90°
m∠D = 2 x 6 + 43 = 12 + 43 = 55°