a) $x = \left( {26\cos {{30}^ \circ }} \right) \times 2.3$

$y = \left( {26\sin {{30}^ \circ }} \right) \times 2.3 + g \times {2.3^2}/2$

${d^2} = {51.8^2} + {56.35^2}$

$d = 76.5{\text{ }}m$

b) $80 = \left( {26\sin {{30}^ \circ }} \right)t + 10{t^2}/2$

$t = 2.91s$ [or $\left( {42.06 - 13} \right)/10$]

$x = \left( {2.906 \times 26\cos {{30}^ \circ }} \right) = 65.4{\text{ }}m$

OR

$80 = x\tan {30^ \circ } + 10{x^2}/\left( {2 \times {{26}^2} \times {{\cos }^2}{{30}^ \circ }} \right)$

$x = 65.4$

c) ${v^2} = {\left( {26\sin {{30}^ \circ }} \right)^2} + 2g \times 80$

${V^2} = {\left( {26\sin {{30}^ \circ }} \right)^2} + 2g \times 80 + {\left( {26\cos {{30}^ \circ }} \right)^2}$

$V = 47.7{\text{ }}m{s^{ - 1}}$

$\alpha  = {\tan ^{ - 1}}\left[ {\left( {42.06} \right)/\left( {26\cos {{30}^ \circ }} \right)} \right] = {61.8^ \circ }$